Author: clamb
Date: Tue Dec 18 14:30:28 2007
New Revision: 45169
URL: http://llvm.org/viewvc/llvm-project?rev=45169&view=rev
Log:
Remove an orthogonal transformation of the selection condition from my most
recent submission.
Modified:
llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
llvm/trunk/test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll
Modified: llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp?rev=45169&r1=45168&r2=45169&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/InstructionCombining.cpp Tue Dec 18
14:30:28 2007
@@ -2131,9 +2131,6 @@
}
}
- // add (select (icmp 0 (sub m A)) X Y) A ->
- // add (select (icmp A m) X Y) A
- //
// add (select X 0 (sub n A)) A ->
// select X A n
{
@@ -2147,27 +2144,6 @@
Value *TV = SI->getTrueValue();
Value *FV = SI->getFalseValue();
Value *A;
-
- // Can we fold the add into the argument of the compare?
- Value *Cond = SI->getCondition();
- if (ICmpInst *IC = dyn_cast<ICmpInst>(Cond)) {
- Value *ICOp0 = IC->getOperand(0);
- Value *ICOp1 = IC->getOperand(1);
- ConstantInt *C3, *C4;
-
- // Check both arguments of the compare for a matching subtract.
- if (match(ICOp0, m_ConstantInt(C3)) && C3->getValue() == 0 &&
- match(ICOp1, m_Sub(m_ConstantInt(C4), m_Value(A))) &&
- A == Other) {
- // We managed to fold the add into the RHS of the select condition.
- Cond = new ICmpInst(IC->getPredicate(), A, C4, "asis", SI);
- } else if (match(ICOp1, m_ConstantInt(C3)) && C3->getValue() == 0 &&
- match(ICOp0, m_Sub(m_ConstantInt(C4), m_Value(A))) &&
- A == Other) {
- // We managed to fold the add into the LHS of the select condition.
- Cond = new ICmpInst(IC->getPredicate(), C4, A, "asis", SI);
- }
- }
// Can we fold the add into the argument of the select?
// We check both true and false select arguments for a matching subtract.
@@ -2177,17 +2153,13 @@
A == Other) {
// We managed to fold the add into the true select value,
// picking up a simplified condition, if available.
- return new SelectInst(Cond, C2, A, "adselsub");
+ return new SelectInst(SI->getCondition(), C2, A);
} else if (match(TV, m_ConstantInt(C1)) && C1->getValue() == 0 &&
match(FV, m_Sub(m_ConstantInt(C2), m_Value(A))) &&
A == Other) {
// We managed to fold the add into the false select value,
// picking up a simplified condition, if available.
- return new SelectInst(Cond, A, C2, "adselsub");
- } else if (Cond != SI->getCondition()) {
- // We only managed to fold the add into the select condition.
- SI->setOperand(0, Cond);
- Changed = true;
+ return new SelectInst(SI->getCondition(), A, C2);
}
}
}
Modified: llvm/trunk/test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll
URL:
http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll?rev=45169&r1=45168&r2=45169&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/2007-12-18-AddSelCmpSub.ll Tue Dec
18 14:30:28 2007
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep {sub}
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep {add} | count 1
define i32 @foo(i32 %a) {
entry:
@@ -19,15 +19,6 @@
ret i32 %tmp12
}
-define i32 @baz(i32 %a) {
-entry:
- %tmp15 = sub i32 99, %a ; <i32> [#uses=1]
- %tmp16 = icmp slt i32 %tmp15, 0 ; <i1> [#uses=1]
- %smax = select i1 %tmp16, i32 0, i32 42 ; <i32> [#uses=1]
- %tmp12 = add i32 %smax, %a ; <i32> [#uses=1]
- ret i32 %tmp12
-}
-
define i32 @fun(i32 %a) {
entry:
%tmp15 = sub i32 99, %a ; <i32> [#uses=1]
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