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authorEli Friedman <eli.friedman@gmail.com>2012-03-16 00:52:42 +0000
committerEli Friedman <eli.friedman@gmail.com>2012-03-16 00:52:42 +0000
commite9f15c8a563a745c5cafa7c98b1f12de2dcab070 (patch)
treedf4af33b10b43d8c5900d38c2d6b9cc994d8df6c
parent213d2e7dc31bef3ceeef0cefa703cb4ce52de51a (diff)
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In InstCombiner::visitOr, make sure we reverse the operand swap used for checking for or-of-xor operations after those checks; a later check expects that any constant will be in Op1. PR12234.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152884 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Transforms/InstCombine/InstCombineAndOrXor.cpp8
-rw-r--r--test/Transforms/InstCombine/2012-3-15-or-xor-constant.ll12
2 files changed, 19 insertions, 1 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
index cc8f5bf43e..1165660f40 100644
--- a/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ b/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -1929,8 +1929,11 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
}
// Canonicalize xor to the RHS.
- if (match(Op0, m_Xor(m_Value(), m_Value())))
+ bool SwappedForXor = false;
+ if (match(Op0, m_Xor(m_Value(), m_Value()))) {
std::swap(Op0, Op1);
+ SwappedForXor = true;
+ }
// A | ( A ^ B) -> A | B
// A | (~A ^ B) -> A | ~B
@@ -1961,6 +1964,9 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
return BinaryOperator::CreateOr(Not, Op0);
}
+ if (SwappedForXor)
+ std::swap(Op0, Op1);
+
if (ICmpInst *RHS = dyn_cast<ICmpInst>(I.getOperand(1)))
if (ICmpInst *LHS = dyn_cast<ICmpInst>(I.getOperand(0)))
if (Value *Res = FoldOrOfICmps(LHS, RHS))
diff --git a/test/Transforms/InstCombine/2012-3-15-or-xor-constant.ll b/test/Transforms/InstCombine/2012-3-15-or-xor-constant.ll
new file mode 100644
index 0000000000..c1602da4c8
--- /dev/null
+++ b/test/Transforms/InstCombine/2012-3-15-or-xor-constant.ll
@@ -0,0 +1,12 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+; PR12234
+
+@g = extern_weak global i32
+define i32 @function(i32 %x) nounwind {
+entry:
+ %xor = xor i32 %x, 1
+ store volatile i32 %xor, i32* inttoptr (i64 1 to i32*), align 4
+ %or4 = or i32 or (i32 zext (i1 icmp eq (i32* @g, i32* null) to i32), i32 1), %xor
+ ret i32 %or4
+}
+; CHECK: define i32 @function