Author: Atmn Patel Date: 2020-11-06T22:06:58-05:00 New Revision: 0b17c6e4479d62bd4ff05c48d6cdf340b198832f
URL: https://github.com/llvm/llvm-project/commit/0b17c6e4479d62bd4ff05c48d6cdf340b198832f DIFF: https://github.com/llvm/llvm-project/commit/0b17c6e4479d62bd4ff05c48d6cdf340b198832f.diff LOG: [LoopDeletion] Allows deletion of possibly infinite side-effect free loops >From C11 and C++11 onwards, a forward-progress requirement has been introduced for both languages. In the case of C, loops with non-constant conditionals that do not have any observable side-effects (as defined by 6.8.5p6) can be assumed by the implementation to terminate, and in the case of C++, this assumption extends to all functions. The clang frontend will emit the `mustprogress` function attribute for C++ functions (D86233, D85393, D86841) and emit the loop metadata `llvm.loop.mustprogress` for every loop in C11 or later that has a non-constant conditional. This patch modifies LoopDeletion so that only loops with the `llvm.loop.mustprogress` metadata or loops contained in functions that are required to make progress (`mustprogress` or `willreturn`) are checked for observable side-effects. If these loops do not have an observable side-effect, then we delete them. Loops without observable side-effects that do not satisfy the above conditions will not be deleted. Reviewed By: jdoerfert Differential Revision: https://reviews.llvm.org/D86844 Added: llvm/test/Transforms/LoopDeletion/mustprogress.ll Modified: clang/test/Misc/loop-opt-setup.c llvm/include/llvm/Transforms/Utils/LoopUtils.h llvm/lib/Transforms/Scalar/LoopDeletion.cpp llvm/lib/Transforms/Utils/LoopUtils.cpp llvm/test/Other/loop-deletion-printer.ll llvm/test/Other/loop-pm-invalidation.ll llvm/test/Transforms/LICM/2003-02-27-PreheaderProblem.ll llvm/test/Transforms/LoopDeletion/2017-07-11-incremental-dt.ll llvm/test/Transforms/LoopDeletion/basic-remark.ll llvm/test/Transforms/LoopDeletion/diundef.ll llvm/test/Transforms/LoopDeletion/invalidation.ll llvm/test/Transforms/LoopDeletion/multiple-exit-conditions.ll llvm/test/Transforms/LoopDeletion/multiple-exits.ll llvm/test/Transforms/LoopDeletion/no-exit-blocks.ll llvm/test/Transforms/LoopDeletion/unreachable-loops.ll llvm/test/Transforms/LoopDeletion/use-in-unreachable.ll llvm/test/Transforms/SCCP/calltest.ll llvm/test/Transforms/SimpleLoopUnswitch/pr37888.ll Removed: ################################################################################ diff --git a/clang/test/Misc/loop-opt-setup.c b/clang/test/Misc/loop-opt-setup.c index 322f5e0e6d4a..43a9f85bca27 100644 --- a/clang/test/Misc/loop-opt-setup.c +++ b/clang/test/Misc/loop-opt-setup.c @@ -25,6 +25,6 @@ void Helper() { // Check br i1 to make sure the loop is gone, there will still be a label branch for the infinite loop. // CHECK-LABEL: Helper -// CHECK: br label +// CHECK: entry: // CHECK-NOT: br i1 -// CHECK: br label +// CHECK-NEXT: ret void diff --git a/llvm/include/llvm/Transforms/Utils/LoopUtils.h b/llvm/include/llvm/Transforms/Utils/LoopUtils.h index d741b5142e5b..076ea2f4453b 100644 --- a/llvm/include/llvm/Transforms/Utils/LoopUtils.h +++ b/llvm/include/llvm/Transforms/Utils/LoopUtils.h @@ -229,6 +229,9 @@ bool hasDisableAllTransformsHint(const Loop *L); /// Look for the loop attribute that disables the LICM transformation heuristics. bool hasDisableLICMTransformsHint(const Loop *L); +/// Look for the loop attribute that requires progress within the loop. +bool hasMustProgress(const Loop *L); + /// The mode sets how eager a transformation should be applied. enum TransformationMode { /// The pass can use heuristics to determine whether a transformation should diff --git a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp index 065db647561e..0db50d06ff26 100644 --- a/llvm/lib/Transforms/Scalar/LoopDeletion.cpp +++ b/llvm/lib/Transforms/Scalar/LoopDeletion.cpp @@ -210,8 +210,10 @@ static LoopDeletionResult deleteLoopIfDead(Loop *L, DominatorTree &DT, // Don't remove loops for which we can't solve the trip count. // They could be infinite, in which case we'd be changing program behavior. const SCEV *S = SE.getConstantMaxBackedgeTakenCount(L); - if (isa<SCEVCouldNotCompute>(S)) { - LLVM_DEBUG(dbgs() << "Could not compute SCEV MaxBackedgeTakenCount.\n"); + if (isa<SCEVCouldNotCompute>(S) && + !L->getHeader()->getParent()->mustProgress() && !hasMustProgress(L)) { + LLVM_DEBUG(dbgs() << "Could not compute SCEV MaxBackedgeTakenCount and was " + "not required to make progress.\n"); return Changed ? LoopDeletionResult::Modified : LoopDeletionResult::Unmodified; } diff --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp index e10a2306547a..4210cd66f3f6 100644 --- a/llvm/lib/Transforms/Utils/LoopUtils.cpp +++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp @@ -63,6 +63,7 @@ static cl::opt<bool> ForceReductionIntrinsic( static const char *LLVMLoopDisableNonforced = "llvm.loop.disable_nonforced"; static const char *LLVMLoopDisableLICM = "llvm.licm.disable"; +static const char *LLVMLoopMustProgress = "llvm.loop.mustprogress"; bool llvm::formDedicatedExitBlocks(Loop *L, DominatorTree *DT, LoopInfo *LI, MemorySSAUpdater *MSSAU, @@ -404,6 +405,10 @@ bool llvm::hasDisableLICMTransformsHint(const Loop *L) { return getBooleanLoopAttribute(L, LLVMLoopDisableLICM); } +bool llvm::hasMustProgress(const Loop *L) { + return getBooleanLoopAttribute(L, LLVMLoopMustProgress); +} + TransformationMode llvm::hasUnrollTransformation(Loop *L) { if (getBooleanLoopAttribute(L, "llvm.loop.unroll.disable")) return TM_SuppressedByUser; diff --git a/llvm/test/Other/loop-deletion-printer.ll b/llvm/test/Other/loop-deletion-printer.ll index 6cb29ae374fb..997905141982 100644 --- a/llvm/test/Other/loop-deletion-printer.ll +++ b/llvm/test/Other/loop-deletion-printer.ll @@ -14,7 +14,7 @@ ; DELETED-BUT-PRINTED: IR Dump {{.*}}LoopDeletionPass {{.*invalidated:}} ; DELETED-BUT-PRINTED-NOT: IR Dump {{.*}}LoopInstSimplifyPass -define void @deleteme() { +define void @deleteme() willreturn { entry: br label %loop loop: diff --git a/llvm/test/Other/loop-pm-invalidation.ll b/llvm/test/Other/loop-pm-invalidation.ll index 9deb17f124d6..e6bd888ed32b 100644 --- a/llvm/test/Other/loop-pm-invalidation.ll +++ b/llvm/test/Other/loop-pm-invalidation.ll @@ -227,7 +227,7 @@ exit: ret void } -define void @dead_loop() { +define void @dead_loop() willreturn { ; CHECK-LOOP-INV: Starting {{.*}}Function pass manager run ; CHECK-LOOP-INV-NEXT: Starting {{.*}}Function pass manager run ; CHECK-LOOP-INV-NEXT: Running pass: LoopSimplifyPass diff --git a/llvm/test/Transforms/LICM/2003-02-27-PreheaderProblem.ll b/llvm/test/Transforms/LICM/2003-02-27-PreheaderProblem.ll index b54d520a91f7..8ff32219d423 100644 --- a/llvm/test/Transforms/LICM/2003-02-27-PreheaderProblem.ll +++ b/llvm/test/Transforms/LICM/2003-02-27-PreheaderProblem.ll @@ -6,7 +6,7 @@ ; RUN: opt < %s -licm -loop-deletion -simplifycfg -S | \ ; RUN: not grep "br " -define i32 @main(i32 %argc) { +define i32 @main(i32 %argc) willreturn { ; <label>:0 br label %bb5 bb5: ; preds = %bb5, %0 diff --git a/llvm/test/Transforms/LoopDeletion/2017-07-11-incremental-dt.ll b/llvm/test/Transforms/LoopDeletion/2017-07-11-incremental-dt.ll index ad8b8b4c6c48..ca1b2ece6294 100644 --- a/llvm/test/Transforms/LoopDeletion/2017-07-11-incremental-dt.ll +++ b/llvm/test/Transforms/LoopDeletion/2017-07-11-incremental-dt.ll @@ -15,7 +15,7 @@ ; DT: [3] %for.body ; DT: [4] %for.cond3.loopexit -define i32 @fn1() { +define i32 @fn1() willreturn { entry: br label %for.cond diff --git a/llvm/test/Transforms/LoopDeletion/basic-remark.ll b/llvm/test/Transforms/LoopDeletion/basic-remark.ll index c56ae9dcb03e..757bb78aa093 100644 --- a/llvm/test/Transforms/LoopDeletion/basic-remark.ll +++ b/llvm/test/Transforms/LoopDeletion/basic-remark.ll @@ -10,7 +10,7 @@ ; CHECK-NEXT: Args: ; CHECK-NEXT: - String: Loop deleted because it is invariant ; CHECK-NEXT: ... -define i32 @main() local_unnamed_addr #0 { +define i32 @main() local_unnamed_addr willreturn { entry: br label %for.cond, !dbg !9 diff --git a/llvm/test/Transforms/LoopDeletion/diundef.ll b/llvm/test/Transforms/LoopDeletion/diundef.ll index 11dc05cb94d2..1245ed5b249f 100644 --- a/llvm/test/Transforms/LoopDeletion/diundef.ll +++ b/llvm/test/Transforms/LoopDeletion/diundef.ll @@ -5,7 +5,7 @@ target triple = "x86_64-apple-macosx10.14.0" @a = common local_unnamed_addr global i32 0, align 4, !dbg !0 -define i32 @b() local_unnamed_addr !dbg !12 { +define i32 @b() local_unnamed_addr willreturn !dbg !12 { entry: call void @llvm.dbg.value(metadata i32 0, metadata !16, metadata !DIExpression()), !dbg !17 br label %for.cond, !dbg !18 diff --git a/llvm/test/Transforms/LoopDeletion/invalidation.ll b/llvm/test/Transforms/LoopDeletion/invalidation.ll index 3f7352672c56..d010f03d706a 100644 --- a/llvm/test/Transforms/LoopDeletion/invalidation.ll +++ b/llvm/test/Transforms/LoopDeletion/invalidation.ll @@ -8,7 +8,7 @@ ; RUN: | FileCheck %s --check-prefixes=CHECK,AFTER -define void @foo(i64 %n, i64 %m) nounwind { +define void @foo(i64 %n, i64 %m) nounwind willreturn { ; CHECK-LABEL: @foo( entry: diff --git a/llvm/test/Transforms/LoopDeletion/multiple-exit-conditions.ll b/llvm/test/Transforms/LoopDeletion/multiple-exit-conditions.ll index e7b47211d570..7231e924ebd0 100644 --- a/llvm/test/Transforms/LoopDeletion/multiple-exit-conditions.ll +++ b/llvm/test/Transforms/LoopDeletion/multiple-exit-conditions.ll @@ -11,7 +11,7 @@ ; CHECK: return: ; CHECK-NEXT: ret void -define void @foo(i64 %n, i64 %m) nounwind { +define void @foo(i64 %n, i64 %m) nounwind willreturn { entry: br label %bb diff --git a/llvm/test/Transforms/LoopDeletion/multiple-exits.ll b/llvm/test/Transforms/LoopDeletion/multiple-exits.ll index 760c3aae4ee7..d418b64d37e5 100644 --- a/llvm/test/Transforms/LoopDeletion/multiple-exits.ll +++ b/llvm/test/Transforms/LoopDeletion/multiple-exits.ll @@ -10,7 +10,7 @@ ; RUN: opt < %s -passes=loop-deletion -S | FileCheck %s --check-prefixes=CHECK,AFTER -define void @foo(i64 %n, i64 %m) nounwind { +define void @foo(i64 %n, i64 %m) #0 { ; CHECK-LABEL: @foo( entry: @@ -43,7 +43,7 @@ return: ; CHECK-NEXT: ret void } -define i64 @bar(i64 %n, i64 %m, i64 %maybe_zero) nounwind { +define i64 @bar(i64 %n, i64 %m, i64 %maybe_zero) #0 { ; CHECK-LABEL: @bar( entry: @@ -95,7 +95,7 @@ return: ; This function has a loop which looks like @bar's but that cannot be deleted ; because which path we exit through determines which value is selected. -define i64 @baz(i64 %n, i64 %m, i64 %maybe_zero) nounwind { +define i64 @baz(i64 %n, i64 %m, i64 %maybe_zero) #0 { ; CHECK-LABEL: @baz( entry: @@ -136,3 +136,5 @@ return: ; CHECK-NEXT: %[[X:.*]] = phi i64 [ 12, %bb ], [ 10, %bb2 ], [ 10, %bb3 ] ; CHECK-NEXT: ret i64 %[[X]] } + +attributes #0 = { nounwind willreturn } \ No newline at end of file diff --git a/llvm/test/Transforms/LoopDeletion/mustprogress.ll b/llvm/test/Transforms/LoopDeletion/mustprogress.ll new file mode 100644 index 000000000000..d94fdb401186 --- /dev/null +++ b/llvm/test/Transforms/LoopDeletion/mustprogress.ll @@ -0,0 +1,237 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --check-attributes +; RUN: opt < %s -loop-deletion -S | FileCheck %s + +;; Original C Code: +;; void unknown_tripcount_mustprogress_attr_mustprogress_loopmd(int a, int b) { +;; for (; a < b;) ; +;; for (;;) ; +;; } + +define void @unknown_tripcount_mustprogress_attr_mustprogress_loopmd(i32 %a, i32 %b) #0 { +; CHECK: Function Attrs: mustprogress +; CHECK-LABEL: define {{[^@]+}}@unknown_tripcount_mustprogress_attr_mustprogress_loopmd +; CHECK-SAME: (i32 [[A:%.*]], i32 [[B:%.*]]) [[ATTR0:#.*]] { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_END:%.*]] +; CHECK: for.end: +; CHECK-NEXT: unreachable +; +entry: + br label %for.cond +for.cond: + %cmp = icmp slt i32 %a, %b + br i1 %cmp, label %for.body, label %for.end +for.body: + br label %for.cond, !llvm.loop !2 +for.end: + br label %for.cond1 +for.cond1: + br label %for.cond1 +} + +;; Original C Code: +;; void unknown_tripcount_mustprogress_attr_no_mustprogress_loopmd(int a, int b) { +;; for (; a < b;) ; +;; for (;;) ; +;; } +;; => Removed mustprogress loop attribute + +define void @unknown_tripcount_mustprogress_attr_no_mustprogess_loopmd(i32 %a, i32 %b) #0 { +; CHECK: Function Attrs: mustprogress +; CHECK-LABEL: define {{[^@]+}}@unknown_tripcount_mustprogress_attr_no_mustprogess_loopmd +; CHECK-SAME: (i32 [[A:%.*]], i32 [[B:%.*]]) [[ATTR0]] { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_END:%.*]] +; CHECK: for.end: +; CHECK-NEXT: unreachable +; +entry: + br label %for.cond +for.cond: + %cmp = icmp slt i32 %a, %b + br i1 %cmp, label %for.body, label %for.end +for.body: + br label %for.cond +for.end: + br label %for.cond1 +for.cond1: + br label %for.cond1 +} + +;; Original C Code: +;; void known_tripcount_no_mustprogress_attr_no_mustprogress_loopmd() { +;; for (int i = 0; i < 5; i++) ; +;; } + +define void @known_tripcount_no_mustprogress_attr_no_mustprogress_loopmd() { +; CHECK-LABEL: define {{[^@]+}}@known_tripcount_no_mustprogress_attr_no_mustprogress_loopmd() { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_END:%.*]] +; CHECK: for.end: +; CHECK-NEXT: ret void +; +entry: + br label %for.cond +for.cond: + %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ] + %cmp = icmp slt i32 %i.0, 5 + br i1 %cmp, label %for.body, label %for.end +for.body: + br label %for.inc +for.inc: + %inc = add nsw i32 %i.0, 1 + br label %for.cond +for.end: + ret void +} + +;; Original C Code: +;; void known_tripcount_no_mustprogress_attr_mustprogress_loopmd() { +;; for (int i = 0; i < 5; i++) ; +;; } +;; => Added mustprogress loop attribute + +define void @known_tripcount_no_mustprogress_attr_mustprogress_loopmd() { +; CHECK-LABEL: define {{[^@]+}}@known_tripcount_no_mustprogress_attr_mustprogress_loopmd() { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_END:%.*]] +; CHECK: for.end: +; CHECK-NEXT: ret void +; +entry: + br label %for.cond +for.cond: + %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ] + %cmp = icmp slt i32 %i.0, 5 + br i1 %cmp, label %for.body, label %for.end +for.body: + br label %for.inc +for.inc: + %inc = add nsw i32 %i.0, 1 + br label %for.cond, !llvm.loop !4 +for.end: + ret void +} + +;; Original C Code: +;; void known_tripcount_mustprogress_attr_no_mustprogress_loopmd() { +;; for (int i = 0; i < 5; i++) ; +;; } +;; => Added mustprogress function attribute + +define void @known_tripcount_mustprogress_attr_no_mustprogress_loopmd() #0 { +; CHECK: Function Attrs: mustprogress +; CHECK-LABEL: define {{[^@]+}}@known_tripcount_mustprogress_attr_no_mustprogress_loopmd +; CHECK-SAME: () [[ATTR0]] { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_END:%.*]] +; CHECK: for.end: +; CHECK-NEXT: ret void +; +entry: + br label %for.cond +for.cond: + %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ] + %cmp = icmp slt i32 %i.0, 5 + br i1 %cmp, label %for.body, label %for.end +for.body: + br label %for.inc +for.inc: + %inc = add nsw i32 %i.0, 1 + br label %for.cond +for.end: + ret void +} + +;; Original C Code: +;; void known_tripcount_mustprogress_attr_mustprogress_loopmd() { +;; for (int i = 0; i < 5; i++) ; +;; } +;; => Added mustprogress function and mustprogress loop attribute + +define void @known_tripcount_mustprogress_attr_mustprogress_loopmd() #0 { +; CHECK: Function Attrs: mustprogress +; CHECK-LABEL: define {{[^@]+}}@known_tripcount_mustprogress_attr_mustprogress_loopmd +; CHECK-SAME: () [[ATTR0]] { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_END:%.*]] +; CHECK: for.end: +; CHECK-NEXT: ret void +; +entry: + br label %for.cond +for.cond: + %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ] + %cmp = icmp slt i32 %i.0, 5 + br i1 %cmp, label %for.body, label %for.end +for.body: + br label %for.inc +for.inc: + %inc = add nsw i32 %i.0, 1 + br label %for.cond, !llvm.loop !5 +for.end: + ret void +} + +;; Original C Code: +;; void unknown_tripcount_no_mustprogress_attr_mustprogress_loopmd(int a, int b) { +;; for (; a < b;) ; +;; } +;; => Added mustprogress loop attribute + +define void @unknown_tripcount_no_mustprogress_attr_mustprogress_loopmd(i32 %a, i32 %b) { +; CHECK-LABEL: define {{[^@]+}}@unknown_tripcount_no_mustprogress_attr_mustprogress_loopmd +; CHECK-SAME: (i32 [[A:%.*]], i32 [[B:%.*]]) { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_END:%.*]] +; CHECK: for.end: +; CHECK-NEXT: ret void +; +entry: + br label %for.cond +for.cond: + %cmp = icmp slt i32 %a, %b + br i1 %cmp, label %for.body, label %for.end +for.body: + br label %for.cond, !llvm.loop !6 +for.end: + ret void +} + +;; Original C Code: +;; void unknown_tripcount_no_mustprogress_attr_no_mustprogress_loopmd(int a, int b) { +;; for (; a < b;) ; +;; } + +define void @unknown_tripcount_no_mustprogress_attr_no_mustprogress_loopmd(i32 %a, i32 %b) { +; CHECK-LABEL: define {{[^@]+}}@unknown_tripcount_no_mustprogress_attr_no_mustprogress_loopmd +; CHECK-SAME: (i32 [[A:%.*]], i32 [[B:%.*]]) { +; CHECK-NEXT: entry: +; CHECK-NEXT: br label [[FOR_COND:%.*]] +; CHECK: for.cond: +; CHECK-NEXT: [[CMP:%.*]] = icmp slt i32 [[A]], [[B]] +; CHECK-NEXT: br i1 [[CMP]], label [[FOR_BODY:%.*]], label [[FOR_END:%.*]] +; CHECK: for.body: +; CHECK-NEXT: br label [[FOR_COND]] +; CHECK: for.end: +; CHECK-NEXT: ret void +; +entry: + br label %for.cond +for.cond: + %cmp = icmp slt i32 %a, %b + br i1 %cmp, label %for.body, label %for.end +for.body: + br label %for.cond +for.end: + ret void +} + +; CHECK: attributes [[ATTR0]] = { mustprogress } + +attributes #0 = { mustprogress } +!2 = distinct !{!2, !3} +!3 = !{!"llvm.loop.mustprogress"} +!4 = distinct !{!4, !3} +!5 = distinct !{!5, !3} +!6 = distinct !{!6, !3} diff --git a/llvm/test/Transforms/LoopDeletion/no-exit-blocks.ll b/llvm/test/Transforms/LoopDeletion/no-exit-blocks.ll index cd790903e8a1..1e68d4f95301 100644 --- a/llvm/test/Transforms/LoopDeletion/no-exit-blocks.ll +++ b/llvm/test/Transforms/LoopDeletion/no-exit-blocks.ll @@ -5,14 +5,7 @@ define void @f() #0 { ; CHECK: Function Attrs: mustprogress ; CHECK-LABEL: define {{[^@]+}}@f ; CHECK-SAME: () [[ATTR0:#.*]] { -; CHECK-NEXT: br label [[TMP1:%.*]] -; CHECK: 1: -; CHECK-NEXT: [[DOT01:%.*]] = phi i32 [ 1, [[TMP0:%.*]] ], [ [[TMP3:%.*]], [[TMP2:%.*]] ] -; CHECK-NEXT: [[DOT0:%.*]] = phi i32 [ 1, [[TMP0]] ], [ [[TMP3]], [[TMP2]] ] -; CHECK-NEXT: br label [[TMP2]] -; CHECK: 2: -; CHECK-NEXT: [[TMP3]] = add nsw i32 [[DOT01]], [[DOT0]] -; CHECK-NEXT: br label [[TMP1]] +; CHECK-NEXT: unreachable ; br label %1 diff --git a/llvm/test/Transforms/LoopDeletion/unreachable-loops.ll b/llvm/test/Transforms/LoopDeletion/unreachable-loops.ll index a74ddf99285e..d4a80b90e933 100644 --- a/llvm/test/Transforms/LoopDeletion/unreachable-loops.ll +++ b/llvm/test/Transforms/LoopDeletion/unreachable-loops.ll @@ -216,7 +216,7 @@ exit: ; Show recursive deletion of loops. Since we start with subloops and progress outward ; to parent loop, we first delete the loop L2. Now loop L1 becomes a non-loop since it's backedge ; from L2's preheader to L1's exit block is never taken. So, L1 gets deleted as well. -define void @test8(i64 %n) { +define void @test8(i64 %n) #0 { ; CHECK-LABEL: test8 ; CHECK-LABEL: entry: ; CHECK-NEXT: br label %exit @@ -318,7 +318,7 @@ exit: ; deleted. ; In the next iteration, since L2 is never executed and has no subloops, we delete ; L2 as well. Finally, the outermost loop L1 is deleted. -define void @test11(i64 %n) { +define void @test11(i64 %n) #0 { ; CHECK-LABEL: test11 ; CHECK-LABEL: entry: ; CHECK-NEXT: br label %exit @@ -355,7 +355,7 @@ exit: ; 2 edges from a single exiting block to the exit block. -define i64 @test12(i64 %n){ +define i64 @test12(i64 %n) #0 { ;CHECK-LABEL: @test12 ; CHECK-NOT: L1: ; CHECK-NOT: L1Latch: @@ -392,7 +392,7 @@ exit: ; preds = %L1Latch, %L1Latch } ; multiple edges to exit block from the same exiting blocks -define i64 @test13(i64 %n) { +define i64 @test13(i64 %n) #0 { ; CHECK-LABEL: @test13 ; CHECK-NOT: L1: ; CHECK-NOT: L1Latch: @@ -433,3 +433,5 @@ exit: ; preds = %L1Block, %L1, %L1La %y.phi = phi i64 [ 10, %L1Block ], [ 10, %L1Block ], [ %y.next, %L1 ], [ 30, %L1Latch ], [ 30, %L1Latch ] ret i64 %y.phi } + +attributes #0 = { willreturn } diff --git a/llvm/test/Transforms/LoopDeletion/use-in-unreachable.ll b/llvm/test/Transforms/LoopDeletion/use-in-unreachable.ll index ff7bc7566c05..3e06e18fd5c3 100644 --- a/llvm/test/Transforms/LoopDeletion/use-in-unreachable.ll +++ b/llvm/test/Transforms/LoopDeletion/use-in-unreachable.ll @@ -3,7 +3,7 @@ ; Checking that possible users of instruction from the loop in ; unreachable blocks are handled. -define i64 @foo() { +define i64 @foo() willreturn { entry: br label %invloop ; CHECK-LABEL-NOT: invloop diff --git a/llvm/test/Transforms/SCCP/calltest.ll b/llvm/test/Transforms/SCCP/calltest.ll index a6c2606cb198..bd49b45c3486 100644 --- a/llvm/test/Transforms/SCCP/calltest.ll +++ b/llvm/test/Transforms/SCCP/calltest.ll @@ -4,7 +4,7 @@ declare double @sqrt(double) readnone nounwind %empty = type {} declare %empty @has_side_effects() -define double @test_0(i32 %param) { +define double @test_0(i32 %param) willreturn { ; CHECK-LABEL: @test_0( ; CHECK-NOT: br entry: diff --git a/llvm/test/Transforms/SimpleLoopUnswitch/pr37888.ll b/llvm/test/Transforms/SimpleLoopUnswitch/pr37888.ll index e8e34a2e8824..ea6d0e5b24a8 100644 --- a/llvm/test/Transforms/SimpleLoopUnswitch/pr37888.ll +++ b/llvm/test/Transforms/SimpleLoopUnswitch/pr37888.ll @@ -7,7 +7,7 @@ target triple = "x86_64-unknown-linux-gnu" -define void @pr37888() { +define void @pr37888() willreturn { ; CHECK-LABEL: define void @pr37888() entry: %tobool = icmp ne i16 undef, 0 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
