jdoerfert created this revision.
jdoerfert added reviewers: homerdin, hfinkel, fedor.sergeev, sanjoy, spatel,
nlopes, nicholas, reames.
Herald added subscribers: cfe-commits, bollu, aheejin, hiraditya, eraman,
sbc100, javed.absar, nhaehnle, jvesely.
Herald added projects: clang, LLVM.
jdoerfert added parent revisions: D59922: [Attributor] Deduce "no-capture"
argument attribute, D59979: [Attributor][NFC] Add helper functions to deal wit
bit-encodings.
Deduce the memory behavior, aka "read-none", "read-only", or
"write-only", for function arguments.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D59980
Files:
clang/test/CodeGen/arm-vfp16-arguments.c
clang/test/CodeGen/systemz-inline-asm.c
clang/test/CodeGenCXX/wasm-args-returns.cpp
clang/test/CodeGenObjC/os_log.m
clang/test/CodeGenOpenCL/amdgpu-abi-struct-coerce.cl
clang/test/CodeGenOpenCL/amdgpu-call-kernel.cl
clang/test/CodeGenOpenCL/kernels-have-spir-cc-by-default.cl
llvm/include/llvm/Transforms/IPO/Attributor.h
llvm/lib/Transforms/IPO/Attributor.cpp
llvm/test/Transforms/FunctionAttrs/SCC1.ll
llvm/test/Transforms/FunctionAttrs/arg_nocapture.ll
llvm/test/Transforms/FunctionAttrs/arg_returned.ll
llvm/test/Transforms/FunctionAttrs/nocapture.ll
llvm/test/Transforms/FunctionAttrs/readattrs.ll
Index: llvm/test/Transforms/FunctionAttrs/readattrs.ll
===================================================================
--- llvm/test/Transforms/FunctionAttrs/readattrs.ll
+++ llvm/test/Transforms/FunctionAttrs/readattrs.ll
@@ -32,7 +32,7 @@
ret void
}
-; CHECK: define void @test5(i8** nocapture %p, i8* %q)
+; CHECK: define void @test5(i8** nocapture writeonly %p, i8* %q)
; Missed optz'n: we could make %q readnone, but don't break test6!
define void @test5(i8** %p, i8* %q) {
store i8* %q, i8** %p
@@ -40,7 +40,7 @@
}
declare void @test6_1()
-; CHECK: define void @test6_2(i8** nocapture %p, i8* %q)
+; CHECK: define void @test6_2(i8** nocapture writeonly %p, i8* %q)
; This is not a missed optz'n.
define void @test6_2(i8** %p, i8* %q) {
store i8* %q, i8** %p
@@ -48,7 +48,7 @@
ret void
}
-; CHECK: define void @test7_1(i32* inalloca nocapture %a)
+; CHECK: define void @test7_1(i32* inalloca nocapture readnone %a)
; inalloca parameters are always considered written
define void @test7_1(i32* inalloca %a) {
ret void
@@ -60,7 +60,7 @@
ret i32* %p
}
-; CHECK: define void @test8_2(i32* nocapture %p)
+; CHECK: define void @test8_2(i32* nocapture writeonly %p)
define void @test8_2(i32* %p) {
entry:
%call = call i32* @test8_1(i32* %p)
Index: llvm/test/Transforms/FunctionAttrs/nocapture.ll
===================================================================
--- llvm/test/Transforms/FunctionAttrs/nocapture.ll
+++ llvm/test/Transforms/FunctionAttrs/nocapture.ll
@@ -134,15 +134,14 @@
ret void
}
-; CHECK: define void @test1_1(i8* nocapture %x1_1, i8* nocapture %y1_1)
-; It would be acceptable to add readnone to %y1_1 and %y1_2.
+; CHECK: define void @test1_1(i8* nocapture readnone %x1_1, i8* nocapture readnone %y1_1)
define void @test1_1(i8* %x1_1, i8* %y1_1) {
call i8* @test1_2(i8* %x1_1, i8* %y1_1)
store i32* null, i32** @g
ret void
}
-; CHECK: define i8* @test1_2(i8* nocapture %x1_2, i8* returned "no-capture-maybe-returned" %y1_2)
+; CHECK: define i8* @test1_2(i8* nocapture readnone %x1_2, i8* readnone returned "no-capture-maybe-returned" %y1_2)
define i8* @test1_2(i8* %x1_2, i8* %y1_2) {
call void @test1_1(i8* %x1_2, i8* %y1_2)
store i32* null, i32** @g
@@ -156,7 +155,7 @@
ret void
}
-; CHECK: define void @test3(i8* nocapture %x3, i8* nocapture readnone %y3, i8* nocapture %z3)
+; CHECK: define void @test3(i8* nocapture readnone %x3, i8* nocapture readnone %y3, i8* nocapture readnone %z3)
define void @test3(i8* %x3, i8* %y3, i8* %z3) {
call void @test3(i8* %z3, i8* %y3, i8* %x3)
store i32* null, i32** @g
@@ -237,7 +236,7 @@
ret void
}
-; CHECK: @nocaptureStrip(i8* nocapture %p)
+; CHECK: @nocaptureStrip(i8* nocapture writeonly %p)
define void @nocaptureStrip(i8* %p) {
entry:
%b = call i8* @llvm.strip.invariant.group.p0i8(i8* %p)
Index: llvm/test/Transforms/FunctionAttrs/arg_returned.ll
===================================================================
--- llvm/test/Transforms/FunctionAttrs/arg_returned.ll
+++ llvm/test/Transforms/FunctionAttrs/arg_returned.ll
@@ -180,8 +180,8 @@
; FNATTR: define dso_local double* @ptr_scc_r1(double* %a, double* readnone %r, double* nocapture readnone %b) [[NoInlineNoUnwindReadnoneUwtable]]
; FNATTR: define dso_local double* @ptr_scc_r2(double* readnone %a, double* readnone %b, double* readnone %r) [[NoInlineNoUnwindReadnoneUwtable]]
;
-; ATTRIBUTOR: define dso_local double* @ptr_sink_r0(double* returned "no-capture-maybe-returned" %r) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
-; ATTRIBUTOR: define dso_local double* @ptr_scc_r1(double* %a, double* returned %r, double* nocapture %b) [[NoInlineNoUnwindReadnoneUwtable]]
+; ATTRIBUTOR: define dso_local double* @ptr_sink_r0(double* readnone returned "no-capture-maybe-returned" %r) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
+; ATTRIBUTOR: define dso_local double* @ptr_scc_r1(double* %a, double* returned %r, double* nocapture readnone %b) [[NoInlineNoUnwindReadnoneUwtable]]
; ATTRIBUTOR: define dso_local double* @ptr_scc_r2(double* %a, double* %b, double* returned %r) [[NoInlineNoUnwindReadnoneUwtable]]
;
; double* ptr_scc_r1(double* a, double* b, double* r);
@@ -266,7 +266,7 @@
; return *a ? a : ret0(ret0(ret0(...ret0(a)...)));
; }
;
-; FEW_IT: define dso_local i32* @ret0(i32* "no-capture-maybe-returned" %a)
+; FEW_IT: define dso_local i32* @ret0(i32* readonly "no-capture-maybe-returned" %a)
; FNATTR: define dso_local i32* @ret0(i32* readonly %a) [[NoInlineNoUnwindUwtable:#[0-9]*]]
; BOTH: define dso_local i32* @ret0(i32* readonly returned "no-capture-maybe-returned" %a) [[NoInlineNoReturnNoUnwindReadonlyUwtable:#[0-9]*]]
define dso_local i32* @ret0(i32* %a) #0 {
@@ -309,7 +309,7 @@
;
; BOTH: define dso_local i32* @calls_unknown_fn(i32* readnone returned "no-capture-maybe-returned" %r) [[NoInlineNoUnwindUwtable]]
; FNATTR: define dso_local i32* @calls_unknown_fn(i32* readnone %r) [[NoInlineNoUnwindUwtable:#[0-9]*]]
-; ATTRIBUTOR: define dso_local i32* @calls_unknown_fn(i32* returned "no-capture-maybe-returned" %r) [[NoInlineNoUnwindUwtable:#[0-9]*]]
+; ATTRIBUTOR: define dso_local i32* @calls_unknown_fn(i32* readnone returned "no-capture-maybe-returned" %r) [[NoInlineNoUnwindUwtable:#[0-9]*]]
;
declare void @unknown_fn(i32* (i32*)*) #0
@@ -417,7 +417,7 @@
; }
;
; FNATTR: define dso_local double* @bitcast(i32* readnone %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
-; ATTRIBUTOR: define dso_local double* @bitcast(i32* returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
+; ATTRIBUTOR: define dso_local double* @bitcast(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
; BOTH: define dso_local double* @bitcast(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
;
define dso_local double* @bitcast(i32* %b) #0 {
@@ -437,7 +437,7 @@
; }
;
; FNATTR: define dso_local double* @bitcasts_select_and_phi(i32* readnone %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
-; ATTRIBUTOR: define dso_local double* @bitcasts_select_and_phi(i32* returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
+; ATTRIBUTOR: define dso_local double* @bitcasts_select_and_phi(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
; BOTH: define dso_local double* @bitcasts_select_and_phi(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
;
define dso_local double* @bitcasts_select_and_phi(i32* %b) #0 {
@@ -472,7 +472,7 @@
; }
;
; FNATTR: define dso_local double* @ret_arg_arg_undef(i32* readnone %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
-; ATTRIBUTOR: define dso_local double* @ret_arg_arg_undef(i32* returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
+; ATTRIBUTOR: define dso_local double* @ret_arg_arg_undef(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
; BOTH: define dso_local double* @ret_arg_arg_undef(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
;
define dso_local double* @ret_arg_arg_undef(i32* %b) #0 {
@@ -507,7 +507,7 @@
; }
;
; FNATTR: define dso_local double* @ret_undef_arg_arg(i32* readnone %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
-; ATTRIBUTOR: define dso_local double* @ret_undef_arg_arg(i32* returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
+; ATTRIBUTOR: define dso_local double* @ret_undef_arg_arg(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
; BOTH: define dso_local double* @ret_undef_arg_arg(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
;
define dso_local double* @ret_undef_arg_arg(i32* %b) #0 {
@@ -542,7 +542,7 @@
; }
;
; FNATTR: define dso_local double* @ret_undef_arg_undef(i32* readnone %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
-; ATTRIBUTOR: define dso_local double* @ret_undef_arg_undef(i32* returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
+; ATTRIBUTOR: define dso_local double* @ret_undef_arg_undef(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoUnwindUwtable]]
; BOTH: define dso_local double* @ret_undef_arg_undef(i32* readnone returned "no-capture-maybe-returned" %b) [[NoInlineNoRecurseNoUnwindReadnoneUwtable]]
;
define dso_local double* @ret_undef_arg_undef(i32* %b) #0 {
Index: llvm/test/Transforms/FunctionAttrs/arg_nocapture.ll
===================================================================
--- llvm/test/Transforms/FunctionAttrs/arg_nocapture.ll
+++ llvm/test/Transforms/FunctionAttrs/arg_nocapture.ll
@@ -128,8 +128,7 @@
;
; CHECK: define dso_local i64* @scc_B(double* readnone returned "no-capture-maybe-returned" %a)
;
-; FIXME: readnone missing for %s
-; CHECK: define dso_local i8* @scc_C(i16* returned "no-capture-maybe-returned" %a)
+; CHECK: define dso_local i8* @scc_C(i16* readnone returned "no-capture-maybe-returned" %a)
;
; float *scc_A(int *a) {
; return (float*)(a ? (int*)scc_A((int*)scc_B((double*)scc_C((short*)a))) : a);
@@ -258,7 +257,7 @@
; }
;
; There should *not* be a no-capture attribute on %a
-; CHECK: define dso_local i64* @not_captured_but_returned_0(i64* returned "no-capture-maybe-returned" %a)
+; CHECK: define dso_local i64* @not_captured_but_returned_0(i64* returned writeonly "no-capture-maybe-returned" %a)
;
define dso_local i64* @not_captured_but_returned_0(i64* %a) #0 {
entry:
@@ -274,7 +273,7 @@
; }
;
; There should *not* be a no-capture attribute on %a
-; CHECK: define dso_local nonnull i64* @not_captured_but_returned_1(i64* "no-capture-maybe-returned" %a)
+; CHECK: define dso_local nonnull i64* @not_captured_but_returned_1(i64* writeonly "no-capture-maybe-returned" %a)
;
define dso_local i64* @not_captured_but_returned_1(i64* %a) #0 {
entry:
@@ -290,7 +289,7 @@
; not_captured_but_returned_1(a);
; }
;
-; CHECK: define dso_local void @test_not_captured_but_returned_calls(i64* nocapture %a)
+; CHECK: define dso_local void @test_not_captured_but_returned_calls(i64* nocapture writeonly %a)
;
define dso_local void @test_not_captured_but_returned_calls(i64* %a) #0 {
entry:
@@ -306,7 +305,7 @@
; }
;
; There should *not* be a no-capture attribute on %a
-; CHECK: define dso_local i64* @negative_test_not_captured_but_returned_call_0a(i64* returned "no-capture-maybe-returned" %a)
+; CHECK: define dso_local i64* @negative_test_not_captured_but_returned_call_0a(i64* returned writeonly "no-capture-maybe-returned" %a)
;
define dso_local i64* @negative_test_not_captured_but_returned_call_0a(i64* %a) #0 {
entry:
@@ -338,7 +337,7 @@
; }
;
; There should *not* be a no-capture attribute on %a
-; CHECK: define dso_local nonnull i64* @negative_test_not_captured_but_returned_call_1a(i64* "no-capture-maybe-returned" %a)
+; CHECK: define dso_local nonnull i64* @negative_test_not_captured_but_returned_call_1a(i64* writeonly "no-capture-maybe-returned" %a)
;
define dso_local i64* @negative_test_not_captured_but_returned_call_1a(i64* %a) #0 {
entry:
@@ -375,10 +374,10 @@
;
; FNATTR: define dso_local i32* @ret_arg_or_unknown(i32* %b)
; FNATTR: define dso_local i32* @ret_arg_or_unknown_through_phi(i32* %b)
-; ATTRIBUTOR: define dso_local i32* @ret_arg_or_unknown(i32* "no-capture-maybe-returned" %b)
-; ATTRIBUTOR: define dso_local i32* @ret_arg_or_unknown_through_phi(i32* "no-capture-maybe-returned" %b)
-; BOTH: define dso_local i32* @ret_arg_or_unknown(i32* "no-capture-maybe-returned" %b)
-; BOTH: define dso_local i32* @ret_arg_or_unknown_through_phi(i32* "no-capture-maybe-returned" %b)
+; ATTRIBUTOR: define dso_local i32* @ret_arg_or_unknown(i32* readnone "no-capture-maybe-returned" %b)
+; ATTRIBUTOR: define dso_local i32* @ret_arg_or_unknown_through_phi(i32* readnone "no-capture-maybe-returned" %b)
+; BOTH: define dso_local i32* @ret_arg_or_unknown(i32* readnone "no-capture-maybe-returned" %b)
+; BOTH: define dso_local i32* @ret_arg_or_unknown_through_phi(i32* readnone "no-capture-maybe-returned" %b)
;
declare dso_local i32* @unknown()
Index: llvm/test/Transforms/FunctionAttrs/SCC1.ll
===================================================================
--- llvm/test/Transforms/FunctionAttrs/SCC1.ll
+++ llvm/test/Transforms/FunctionAttrs/SCC1.ll
@@ -46,7 +46,7 @@
;
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-; CHECK: define dso_local i32* @external_ret2_nrw(i32* nocapture %n0, i32* nocapture %r0, i32* returned "no-capture-maybe-returned" %w0) #[[NOUNWIND:[0-9]*]]
+; CHECK: define dso_local i32* @external_ret2_nrw(i32* nocapture readnone %n0, i32* nocapture readonly %r0, i32* returned writeonly "no-capture-maybe-returned" %w0) #[[NOUNWIND:[0-9]*]]
define dso_local i32* @external_ret2_nrw(i32* %n0, i32* %r0, i32* %w0) {
entry:
%call = call i32* @internal_ret0_nw(i32* %n0, i32* %w0)
@@ -56,7 +56,7 @@
ret i32* %call3
}
-; CHECK: define internal i32* @internal_ret0_nw(i32* returned "no-capture-maybe-returned" %n0, i32* nocapture %w0) #[[NOUNWIND]]
+; CHECK: define internal i32* @internal_ret0_nw(i32* readnone returned "no-capture-maybe-returned" %n0, i32* nocapture writeonly %w0) #[[NOUNWIND]]
define internal i32* @internal_ret0_nw(i32* %n0, i32* %w0) {
entry:
%r0 = alloca i32, align 4
@@ -84,7 +84,7 @@
ret i32* %retval.0
}
-; CHECK: define internal i32* @internal_ret1_rrw(i32* nocapture %r0, i32* returned "no-capture-maybe-returned" %r1, i32* nocapture %w0) #[[NOUNWIND]]
+; CHECK: define internal i32* @internal_ret1_rrw(i32* nocapture readonly %r0, i32* readonly returned "no-capture-maybe-returned" %r1, i32* nocapture writeonly %w0) #[[NOUNWIND]]
define internal i32* @internal_ret1_rrw(i32* %r0, i32* %r1, i32* %w0) {
entry:
%0 = load i32, i32* %r0, align 4
@@ -115,7 +115,7 @@
ret i32* %retval.0
}
-; CHECK: define dso_local i32* @external_sink_ret2_nrw(i32* nocapture readnone %n0, i32* nocapture readonly %r0, i32* returned "no-capture-maybe-returned" %w0) #[[NOREC_NOUNWIND:[0-9]*]]
+; CHECK: define dso_local i32* @external_sink_ret2_nrw(i32* nocapture readnone %n0, i32* nocapture readonly %r0, i32* returned writeonly "no-capture-maybe-returned" %w0) #[[NOREC_NOUNWIND:[0-9]*]]
define dso_local i32* @external_sink_ret2_nrw(i32* %n0, i32* %r0, i32* %w0) {
entry:
%tobool = icmp ne i32* %n0, null
@@ -133,7 +133,7 @@
ret i32* %w0
}
-; CHECK: define internal i32* @internal_ret1_rw(i32* nocapture %r0, i32* returned "no-capture-maybe-returned" %w0) #[[NOUNWIND]]
+; CHECK: define internal i32* @internal_ret1_rw(i32* nocapture readonly %r0, i32* returned writeonly "no-capture-maybe-returned" %w0) #[[NOUNWIND]]
define internal i32* @internal_ret1_rw(i32* %r0, i32* %w0) {
entry:
%0 = load i32, i32* %r0, align 4
@@ -158,7 +158,7 @@
ret i32* %retval.0
}
-; CHECK: define dso_local i32* @external_source_ret2_nrw(i32* nocapture %n0, i32* nocapture %r0, i32* returned "no-capture-maybe-returned" %w0) #[[NOUNWIND]]
+; CHECK: define dso_local i32* @external_source_ret2_nrw(i32* nocapture readnone %n0, i32* nocapture readonly %r0, i32* returned writeonly "no-capture-maybe-returned" %w0) #[[NOUNWIND]]
define dso_local i32* @external_source_ret2_nrw(i32* %n0, i32* %r0, i32* %w0) {
entry:
%call = call i32* @external_sink_ret2_nrw(i32* %n0, i32* %r0, i32* %w0)
Index: llvm/lib/Transforms/IPO/Attributor.cpp
===================================================================
--- llvm/lib/Transforms/IPO/Attributor.cpp
+++ llvm/lib/Transforms/IPO/Attributor.cpp
@@ -50,6 +50,13 @@
STATISTIC(NumFnArgumentNoCapture,
"Number of function arguments marked no-capture");
+STATISTIC(NumFnArgumentReadNone,
+ "Number of function arguments marked read-none");
+STATISTIC(NumFnArgumentReadOnly,
+ "Number of function arguments marked read-only");
+STATISTIC(NumFnArgumentWriteOnly,
+ "Number of function arguments marked write-only");
+
// TODO: Determine a good default value.
static cl::opt<unsigned>
MaxFixpointIterations("attributor-max-iterations", cl::Hidden,
@@ -154,6 +161,15 @@
case Attribute::NoReturn:
NumFnNoReturn++;
return;
+ case Attribute::ReadNone:
+ NumFnArgumentReadNone++;
+ return;
+ case Attribute::ReadOnly:
+ NumFnArgumentReadOnly++;
+ return;
+ case Attribute::WriteOnly:
+ NumFnArgumentWriteOnly++;
+ return;
default:
return;
}
@@ -961,6 +977,319 @@
: ChangeStatus::CHANGED;
}
+/// -------------------- Memory Behavior Attributes ----------------------------
+/// Includes read-none, read-only, and write-only.
+/// ----------------------------------------------------------------------------
+
+/// A class to hold the state of for memory behaviour attributes.
+///
+/// The state is encoded in the bits of the "char" variables known and assumed
+/// as defined by the encoding bits.
+struct AAMemoryBehaviorImpl : public AAMemoryBehavior,
+ IntegerState<char, 0, 3> {
+
+ AAMemoryBehaviorImpl(Value &V) : AAMemoryBehavior(V) {
+ assert(getAssumed() == BEST_STATE && "Expected optimistic initialization!");
+ }
+
+ /// State encoding bits. A set bit in the state means the property holds.
+ /// BEST_STATE is the best possible state, 0 the worst possible state.
+ enum {
+ NO_READS = 1 << 0,
+ NO_WRITES = 1 << 1,
+ NO_ACCESSES = NO_READS | NO_WRITES,
+
+ BEST_STATE = NO_ACCESSES,
+ };
+
+ /// See AAMemoryBehavior::isKnownReadNone();
+ virtual bool isKnownReadNone() const override {
+ return testBits(getKnown(), NO_ACCESSES);
+ }
+
+ /// See AAMemoryBehavior::isAssumedReadNone();
+ virtual bool isAssumedReadNone() const override {
+ return testBits(getAssumed(), NO_ACCESSES);
+ }
+
+ /// See AAMemoryBehavior::isKnownReadOnly();
+ virtual bool isKnownReadOnly() const override {
+ return testBits(getKnown(), NO_WRITES);
+ }
+
+ /// See AAMemoryBehavior::isAssumedReadOnly();
+ virtual bool isAssumedReadOnly() const override {
+ return testBits(getAssumed(), NO_WRITES);
+ }
+
+ /// See AAMemoryBehavior::isKnownWriteOnly();
+ virtual bool isKnownWriteOnly() const override {
+ return testBits(getKnown(), NO_READS);
+ }
+
+ /// See AAMemoryBehavior::isAssumedWriteOnly();
+ virtual bool isAssumedWriteOnly() const override {
+ return testBits(getAssumed(), NO_READS);
+ }
+
+ /// See AbstractState::getAsStr().
+ const std::string getAsStr() const override {
+ std::string S = "";
+ if (isAssumedReadNone())
+ S = "readnone";
+ else if (isAssumedReadOnly())
+ S = "readonly";
+ else if (isAssumedWriteOnly())
+ S = "writeonly";
+ else
+ S = "may-read/write";
+
+ return S;
+ }
+
+ /// Extract the memory behavior information of \p V encoded in the IR.
+ static decltype(Known) getKnownStateFromValue(const Value &V);
+
+ /// See AbstractAttribute::getDeducedAttributes(Attributor &A).
+ virtual void
+ getDeducedAttributes(SmallVectorImpl<Attribute> &Attrs) const override;
+
+ /// See AbstractAttribute::getState()
+ ///{
+ AbstractState &getState() override { return *this; }
+ const AbstractState &getState() const override { return *this; }
+ ///}
+};
+
+decltype(AAMemoryBehaviorImpl::Known)
+AAMemoryBehaviorImpl::getKnownStateFromValue(const Value &V) {
+ decltype(AAMemoryBehaviorImpl::Known) Known = 0;
+
+ if (const Argument *Arg = dyn_cast<Argument>(&V)) {
+ if (Arg->hasAttribute(Attribute::ReadNone))
+ setBits(Known, NO_ACCESSES);
+ else if (Arg->hasAttribute(Attribute::ReadOnly))
+ setBits(Known, NO_WRITES);
+ else if (Arg->hasAttribute(Attribute::WriteOnly))
+ setBits(Known, NO_READS);
+ }
+
+ return Known;
+}
+
+void AAMemoryBehaviorImpl::getDeducedAttributes(
+ SmallVectorImpl<Attribute> &Attrs) const {
+ LLVMContext &Ctx = getAnchoredValue().getContext();
+ assert(Attrs.size() == 0);
+ if (isAssumedReadNone())
+ Attrs.push_back(Attribute::get(Ctx, Attribute::ReadNone));
+ else if (isAssumedReadOnly())
+ Attrs.push_back(Attribute::get(Ctx, Attribute::ReadOnly));
+ else if (isAssumedWriteOnly())
+ Attrs.push_back(Attribute::get(Ctx, Attribute::WriteOnly));
+ assert(Attrs.size() <= 1);
+}
+
+/// An AA to represent the memory behavior argument attributes.
+struct AAMemoryBehaviorArgument final : public AAMemoryBehaviorImpl {
+
+ /// See AAMemoryBehaviorImpl::AAMemoryBehaviorImpl(...).
+ AAMemoryBehaviorArgument(Argument &Arg) : AAMemoryBehaviorImpl(Arg) {}
+
+ /// See AbstractAttribute::initialize(...).
+ void initialize(Attributor &A) override {
+ Argument &Arg = cast<Argument>(getAnchoredValue());
+
+ if (Arg.getNumUses() == 0)
+ setBits(Known, NO_ACCESSES);
+ else
+ Known = getKnownStateFromValue(Arg);
+ }
+
+ /// See AbstractAttribute::updateImpl(Attributor &A).
+ virtual ChangeStatus updateImpl(Attributor &A) override;
+
+ /// See AbstractAttribute::getManifestPosition().
+ virtual ManifestPosition getManifestPosition() const override {
+ return MP_ARGUMENT;
+ }
+
+ /// See AbstractAttribute::manifest(Attributor &A).
+ virtual ChangeStatus manifest(Attributor &A) override;
+
+private:
+ /// Return true if users of \p UserI might access the underlying
+ /// variable/location described by \p U.
+ bool followUseIn(Attributor &A, const Use *U, const Instruction *UserI);
+
+ /// Update the state according to the effect of use \p U in \p UserI.
+ void analyzeUseIn(Attributor &A, const Use *U, const Instruction *UserI);
+
+ /// Container for (transitive) uses of the associated argument.
+ SmallVector<const Use *, 32> Uses;
+
+ /// Container for visited (transitive) uses of the associated argument.
+ SmallPtrSet<const Use *, 32> VisitedUses;
+};
+
+ChangeStatus AAMemoryBehaviorArgument::manifest(Attributor &A) {
+ Argument &Arg = cast<Argument>(getAnchoredValue());
+
+ // Check if we would improve the existing attributes first.
+ decltype(Assumed) ExistingState = getKnownStateFromValue(Arg);
+ if (testBits(ExistingState, Assumed))
+ return ChangeStatus::UNCHANGED;
+
+ // Remove existing attributes as they not always mix well with derived ones.
+ Arg.removeAttr(Attribute::ReadNone);
+ Arg.removeAttr(Attribute::ReadOnly);
+ Arg.removeAttr(Attribute::WriteOnly);
+ return AbstractAttribute::manifest(A);
+}
+
+bool AAMemoryBehaviorArgument::followUseIn(Attributor &A, const Use *U,
+ const Instruction *UserI) {
+ if (isa<LoadInst>(UserI)) {
+ // The loaded value is unrelated to the pointer argument, no need to
+ // follow the users of the load.
+ return false;
+ }
+
+ ImmutableCallSite ICS(UserI);
+ if (ICS) {
+ if (!ICS.isArgOperand(U))
+ return true;
+
+ // If the use is a call argument known not to be captured, the users of
+ // the call do not need to be visited because they have to be unrelated to
+ // the input. Note that this check is not trivial even though we disallow
+ // general capturing of the underlying argument. The reason is that the
+ // call might the argument "through return", which we allow and for which we
+ // need to check call users.
+ unsigned ArgNo = ICS.getArgumentNo(U);
+ AANoCapture *ArgNoCaptureAA =
+ A.getAAFor<AANoCapture>(*this, *ICS.getCalledValue(), ArgNo);
+ if (ArgNoCaptureAA && ArgNoCaptureAA->isAssumedNoCapture())
+ return false;
+ }
+
+ // By default we follow all uses assuming UserI might leak information on U.
+ return true;
+}
+
+void AAMemoryBehaviorArgument::analyzeUseIn(Attributor &A, const Use *U,
+ const Instruction *UserI) {
+ assert(UserI->mayReadOrWriteMemory());
+
+ switch (UserI->getOpcode()) {
+ case Instruction::Load:
+ // Loads cause the NO_READS property to disappear.
+ setBits(unsetBits(Assumed, NO_READS), Known);
+ return;
+
+ case Instruction::Store:
+ // Stores cause the NO_WRITES property to disappear if the use is the
+ // pointer operand. Note that we do assume that capturing was taken care of
+ // somewhere else.
+ if (cast<StoreInst>(UserI)->getPointerOperand() == U->get())
+ setBits(unsetBits(Assumed, NO_WRITES), Known);
+ return;
+
+ case Instruction::Call:
+ case Instruction::Invoke: {
+ ImmutableCallSite ICS(UserI);
+ // For call sites we look at the argument memory behavior attribute (this
+ // could be recursive!) in order to restrict our own state. Note that
+ // operand bundle uses are "OK" here because we know that the argument did
+ // not espace and the general behavior of the instruction is taken into
+ // account below.
+ if (ICS.isArgOperand(U)) {
+ unsigned ArgNo = ICS.getArgumentNo(U);
+
+ // Adjust the possible access behavior based on the information on the
+ // argument.
+ auto *ArgMemAccBehavior = A.getAAFor<AAMemoryBehaviorArgument>(
+ *this, *ICS.getCalledValue(), ArgNo);
+ if (ArgMemAccBehavior && ArgMemAccBehavior->getState().isValidState()) {
+ // "assumed" has at most the same bits as the ArgMemAccBehavior assumed
+ // and at least "known".
+ setBits(intersectBits(Assumed, ArgMemAccBehavior->getAssumed()), Known);
+ return;
+ }
+
+ if (const Function *Callee = ICS.getCalledFunction()) {
+ if (Callee->arg_size() > ArgNo) {
+ // "assumed" has at most the same bits known to hold for the argument
+ // and at least "known".
+ const Argument &CalleeArg = *(Callee->arg_begin() + ArgNo);
+ setBits(intersectBits(Assumed, getKnownStateFromValue(CalleeArg)),
+ Known);
+ return;
+ }
+ }
+ }
+ break;
+ }
+ };
+
+ // Generally, look at the "may-properties" and adjust the assumed state.
+ if (UserI->mayReadFromMemory())
+ setBits(unsetBits(Assumed, NO_READS), Known);
+ if (UserI->mayWriteToMemory())
+ setBits(unsetBits(Assumed, NO_WRITES), Known);
+}
+
+ChangeStatus AAMemoryBehaviorArgument::updateImpl(Attributor &A) {
+ assert(isAssumedReadOnly() || isAssumedWriteOnly());
+
+ // The associated argument.
+ Argument &Arg = cast<Argument>(getAnchoredValue());
+
+ // First make sure the argument is not captured (except through "return"), if
+ // it is, any information derived would be irrelevant anyway.
+ if (!Arg.hasNoCaptureAttr()) {
+ AANoCapture *ArgNoCaptureAA = A.getAAFor<AANoCapture>(*this, Arg);
+ if (!ArgNoCaptureAA || !ArgNoCaptureAA->isAssumedNoCaptureMaybeReturned()) {
+ assert(!isAtFixpoint());
+ indicateFixpoint(/* Optimistic */ false);
+ return ChangeStatus::CHANGED;
+ }
+ }
+
+ // The current assumed state used to determine a change.
+ auto AssumedState = getAssumed();
+
+ // The first time update is called we initialize the use vector with all
+ // direct argument uses. Transitive uses are collected every time because the
+ // need to explore more of them may only be known in subsequent updates.
+ bool ExploreUses = VisitedUses.empty();
+ if (ExploreUses) {
+ for (const Use &U : Arg.uses())
+ if (VisitedUses.insert(&U).second)
+ Uses.push_back(&U);
+ }
+
+ // Visit and expand uses until all are analyzed or a fixpoint is reached.
+ for (unsigned i = 0; i < Uses.size() && !isAtFixpoint(); i++) {
+ const Use *U = Uses[i];
+ Instruction *UserI = cast<Instruction>(U->getUser());
+
+ // Check if the users of UserI should also be visited.
+ if (followUseIn(A, U, UserI))
+ for (const Use &UserIUse : UserI->uses())
+ if (VisitedUses.insert(&UserIUse).second)
+ Uses.push_back(&UserIUse);
+
+ // If UserI might touch memory we analyze the use in detail.
+ if (UserI->mayReadOrWriteMemory())
+ analyzeUseIn(A, U, UserI);
+ }
+
+ assert(testBits(Assumed, Known) && "Update created an invalid state!");
+ return (AssumedState != getAssumed()) ? ChangeStatus::CHANGED
+ : ChangeStatus::UNCHANGED;
+}
+
/// ----------------------------------------------------------------------------
/// Attributor
/// ----------------------------------------------------------------------------
@@ -1152,6 +1481,7 @@
// is also derived but as a "function return attribute" (see above).
if (Arg.getType()->isPointerTy()) {
registerAA(*new AANoCaptureArgument(Arg));
+ registerAA(*new AAMemoryBehaviorArgument(Arg));
}
}
Index: llvm/include/llvm/Transforms/IPO/Attributor.h
===================================================================
--- llvm/include/llvm/Transforms/IPO/Attributor.h
+++ llvm/include/llvm/Transforms/IPO/Attributor.h
@@ -281,6 +281,45 @@
static constexpr Attribute::AttrKind ID = Attribute::NoCapture;
};
+/// An abstract interface for all nocapture attributes.
+struct AAMemoryBehavior : public AbstractAttribute {
+
+ /// See AbstractAttribute::AbstractAttribute(...).
+ AAMemoryBehavior(Value &V) : AbstractAttribute(V) {}
+
+ /// Return true if we know that the underlying value is not read or accessed
+ /// in its respective scope.
+ virtual bool isKnownReadNone() const = 0;
+
+ /// Return true if we assume that the underlying value is not read or accessed
+ /// in its respective scope.
+ virtual bool isAssumedReadNone() const = 0;
+
+ /// Return true if we know that the underlying value is not accessed
+ /// (=written) in its respective scope.
+ virtual bool isKnownReadOnly() const = 0;
+
+ /// Return true if we assume that the underlying value is not accessed
+ /// (=written) in its respective scope.
+ virtual bool isAssumedReadOnly() const = 0;
+
+ /// Return true if we know that the underlying value is not read in its
+ /// respective scope.
+ virtual bool isKnownWriteOnly() const = 0;
+
+ /// Return true if we assume that the underlying value is not read in its
+ /// respective scope.
+ virtual bool isAssumedWriteOnly() const = 0;
+
+ /// See AbstractState::getAttrKind().
+ Attribute::AttrKind getAttrKind() const override {
+ return ID;
+ }
+
+ /// The identifier used by the Attributor for this class of attributes.
+ static constexpr Attribute::AttrKind ID = Attribute::ReadNone;
+};
+
/// ----------------------------------------------------------------------------
/// Pass (Manager) Boilerplate
/// ----------------------------------------------------------------------------
Index: clang/test/CodeGenOpenCL/kernels-have-spir-cc-by-default.cl
===================================================================
--- clang/test/CodeGenOpenCL/kernels-have-spir-cc-by-default.cl
+++ clang/test/CodeGenOpenCL/kernels-have-spir-cc-by-default.cl
@@ -28,7 +28,7 @@
// CHECK: spir_kernel
// AMDGCN: define amdgpu_kernel void @test_single
// CHECK: struct.int_single* byval nocapture
-// CHECK: i32* nocapture %output
+// CHECK: i32* nocapture writeonly %output
output[0] = input.a;
}
@@ -36,7 +36,7 @@
// CHECK: spir_kernel
// AMDGCN: define amdgpu_kernel void @test_pair
// CHECK: struct.int_pair* byval nocapture
-// CHECK: i32* nocapture %output
+// CHECK: i32* nocapture writeonly %output
output[0] = (int)input.a;
output[1] = (int)input.b;
}
@@ -45,7 +45,7 @@
// CHECK: spir_kernel
// AMDGCN: define amdgpu_kernel void @test_kernel
// CHECK: struct.test_struct* byval nocapture
-// CHECK: i32* nocapture %output
+// CHECK: i32* nocapture writeonly %output
output[0] = input.elementA;
output[1] = input.elementB;
output[2] = (int)input.elementC;
@@ -59,7 +59,7 @@
void test_function(int_pair input, global int* output) {
// CHECK-NOT: spir_kernel
// AMDGCN-NOT: define amdgpu_kernel void @test_function
-// CHECK: i64 %input.coerce0, i64 %input.coerce1, i32* nocapture %output
+// CHECK: i64 %input.coerce0, i64 %input.coerce1, i32* nocapture writeonly %output
output[0] = (int)input.a;
output[1] = (int)input.b;
}
Index: clang/test/CodeGenOpenCL/amdgpu-call-kernel.cl
===================================================================
--- clang/test/CodeGenOpenCL/amdgpu-call-kernel.cl
+++ clang/test/CodeGenOpenCL/amdgpu-call-kernel.cl
@@ -1,6 +1,6 @@
// REQUIRES: amdgpu-registered-target
// RUN: %clang_cc1 -triple amdgcn-unknown-unknown -S -emit-llvm -o - %s | FileCheck %s
-// CHECK: define amdgpu_kernel void @test_call_kernel(i32 addrspace(1)* nocapture %out)
+// CHECK: define amdgpu_kernel void @test_call_kernel(i32 addrspace(1)* nocapture writeonly %out)
// CHECK: store i32 4, i32 addrspace(1)* %out, align 4
kernel void test_kernel(global int *out)
Index: clang/test/CodeGenOpenCL/amdgpu-abi-struct-coerce.cl
===================================================================
--- clang/test/CodeGenOpenCL/amdgpu-abi-struct-coerce.cl
+++ clang/test/CodeGenOpenCL/amdgpu-abi-struct-coerce.cl
@@ -309,7 +309,7 @@
// CHECK: void @func_different_size_type_pair_arg(i64 %arg1.coerce0, i32 %arg1.coerce1)
void func_different_size_type_pair_arg(different_size_type_pair arg1) { }
-// CHECK: void @func_flexible_array_arg(%struct.flexible_array addrspace(5)* byval nocapture align 4 %arg)
+// CHECK: void @func_flexible_array_arg(%struct.flexible_array addrspace(5)* byval nocapture readnone align 4 %arg)
void func_flexible_array_arg(flexible_array arg) { }
// CHECK: define float @func_f32_ret()
@@ -404,14 +404,14 @@
return s;
}
-// CHECK: define void @func_ret_struct_arr32(%struct.struct_arr32 addrspace(5)* noalias nocapture sret %agg.result)
+// CHECK: define void @func_ret_struct_arr32(%struct.struct_arr32 addrspace(5)* noalias nocapture sret writeonly %agg.result)
struct_arr32 func_ret_struct_arr32()
{
struct_arr32 s = { 0 };
return s;
}
-// CHECK: define void @func_ret_struct_arr33(%struct.struct_arr33 addrspace(5)* noalias nocapture sret %agg.result)
+// CHECK: define void @func_ret_struct_arr33(%struct.struct_arr33 addrspace(5)* noalias nocapture sret writeonly %agg.result)
struct_arr33 func_ret_struct_arr33()
{
struct_arr33 s = { 0 };
@@ -440,7 +440,7 @@
return s;
}
-// CHECK: define void @func_flexible_array_ret(%struct.flexible_array addrspace(5)* noalias nocapture sret %agg.result)
+// CHECK: define void @func_flexible_array_ret(%struct.flexible_array addrspace(5)* noalias nocapture sret writeonly %agg.result)
flexible_array func_flexible_array_ret()
{
flexible_array s = { 0 };
Index: clang/test/CodeGenObjC/os_log.m
===================================================================
--- clang/test/CodeGenObjC/os_log.m
+++ clang/test/CodeGenObjC/os_log.m
@@ -14,7 +14,7 @@
#ifdef __x86_64__
// CHECK-LABEL: define i8* @test_builtin_os_log
// CHECK-O0-LABEL: define i8* @test_builtin_os_log
-// CHECK: (i8* returned "no-capture-maybe-returned" %[[BUF:.*]])
+// CHECK: (i8* returned writeonly "no-capture-maybe-returned" %[[BUF:.*]])
// CHECK-O0: (i8* %[[BUF:.*]])
void *test_builtin_os_log(void *buf) {
return __builtin_os_log_format(buf, "capabilities: %@", GenString());
Index: clang/test/CodeGenCXX/wasm-args-returns.cpp
===================================================================
--- clang/test/CodeGenCXX/wasm-args-returns.cpp
+++ clang/test/CodeGenCXX/wasm-args-returns.cpp
@@ -30,7 +30,7 @@
double d, e;
};
test(two_fields);
-// CHECK: define void @_Z7forward10two_fields(%struct.two_fields* noalias nocapture sret %{{.*}}, %struct.two_fields* byval nocapture readonly align 8 %{{.*}})
+// CHECK: define void @_Z7forward10two_fields(%struct.two_fields* noalias nocapture sret writeonly %{{.*}}, %struct.two_fields* byval nocapture readonly align 8 %{{.*}})
//
// CHECK: define void @_Z15test_two_fieldsv()
// CHECK: %[[tmp:.*]] = alloca %struct.two_fields, align 8
Index: clang/test/CodeGen/systemz-inline-asm.c
===================================================================
--- clang/test/CodeGen/systemz-inline-asm.c
+++ clang/test/CodeGen/systemz-inline-asm.c
@@ -123,7 +123,7 @@
long double test_f128(long double f, long double g) {
asm("axbr %0, %2" : "=f" (f) : "0" (f), "f" (g));
return f;
-// CHECK: define void @test_f128(fp128* noalias nocapture sret [[DEST:%.*]], fp128* nocapture readonly, fp128* nocapture readonly)
+// CHECK: define void @test_f128(fp128* noalias nocapture sret writeonly [[DEST:%.*]], fp128* nocapture readonly, fp128* nocapture readonly)
// CHECK: %f = load fp128, fp128* %0
// CHECK: %g = load fp128, fp128* %1
// CHECK: [[RESULT:%.*]] = tail call fp128 asm "axbr $0, $2", "=f,0,f"(fp128 %f, fp128 %g)
Index: clang/test/CodeGen/arm-vfp16-arguments.c
===================================================================
--- clang/test/CodeGen/arm-vfp16-arguments.c
+++ clang/test/CodeGen/arm-vfp16-arguments.c
@@ -71,6 +71,6 @@
hfa_t ghfa;
hfa_t test_ret_hfa(void) { return ghfa; }
-// CHECK-SOFT: define void @test_ret_hfa(%struct.hfa_t* noalias nocapture sret %agg.result)
+// CHECK-SOFT: define void @test_ret_hfa(%struct.hfa_t* noalias nocapture sret writeonly %agg.result)
// CHECK-HARD: define arm_aapcs_vfpcc [2 x <2 x i32>] @test_ret_hfa()
// CHECK-FULL: define arm_aapcs_vfpcc %struct.hfa_t @test_ret_hfa()
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