duncan's spider sense was right, I completely reversed the condition

on this instcombine xform.  This fixes a miscompilation of 403.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119988 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2010-11-23 02:42:04 +00:00
parent 2e1a75d6f4
commit 79b967bd9f
2 changed files with 12 additions and 12 deletions

View File

@ -1761,22 +1761,22 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
LHS = Op0;
// If the LHS is 1 << x, and we know the result is a power of 2 like 8,
// then turn "((1 << x)&8) == 0" into "x == 3".
// then turn "((1 << x)&8) == 0" into "x != 3".
Value *X = 0;
if (match(LHS, m_Shl(m_One(), m_Value(X)))) {
unsigned CmpVal = Op0KnownZeroInverted.countTrailingZeros();
return new ICmpInst(ICmpInst::ICMP_EQ, X,
return new ICmpInst(ICmpInst::ICMP_NE, X,
ConstantInt::get(X->getType(), CmpVal));
}
// If the LHS is 8 >>u x, and we know the result is a power of 2 like 1,
// then turn "((8 >>u x)&1) == 0" into "x == 3".
// then turn "((8 >>u x)&1) == 0" into "x != 3".
ConstantInt *CI = 0;
if (Op0KnownZeroInverted == 1 &&
match(LHS, m_LShr(m_ConstantInt(CI), m_Value(X))) &&
CI->getValue().isPowerOf2()) {
unsigned CmpVal = CI->getValue().countTrailingZeros();
return new ICmpInst(ICmpInst::ICMP_EQ, X,
return new ICmpInst(ICmpInst::ICMP_NE, X,
ConstantInt::get(X->getType(), CmpVal));
}
}
@ -1800,22 +1800,22 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) {
LHS = Op0;
// If the LHS is 1 << x, and we know the result is a power of 2 like 8,
// then turn "((1 << x)&8) != 0" into "x != 3".
// then turn "((1 << x)&8) != 0" into "x == 3".
Value *X = 0;
if (match(LHS, m_Shl(m_One(), m_Value(X)))) {
unsigned CmpVal = Op0KnownZeroInverted.countTrailingZeros();
return new ICmpInst(ICmpInst::ICMP_NE, X,
return new ICmpInst(ICmpInst::ICMP_EQ, X,
ConstantInt::get(X->getType(), CmpVal));
}
// If the LHS is 8 >>u x, and we know the result is a power of 2 like 1,
// then turn "((8 >>u x)&1) != 0" into "x != 3".
// then turn "((8 >>u x)&1) != 0" into "x == 3".
ConstantInt *CI = 0;
if (Op0KnownZeroInverted == 1 &&
match(LHS, m_LShr(m_ConstantInt(CI), m_Value(X))) &&
CI->getValue().isPowerOf2()) {
unsigned CmpVal = CI->getValue().countTrailingZeros();
return new ICmpInst(ICmpInst::ICMP_NE, X,
return new ICmpInst(ICmpInst::ICMP_EQ, X,
ConstantInt::get(X->getType(), CmpVal));
}
}

View File

@ -161,7 +161,7 @@ define i1 @test17(i32 %x) nounwind {
%cmp = icmp eq i32 %and, 0
ret i1 %cmp
; CHECK: @test17
; CHECK-NEXT: %cmp = icmp eq i32 %x, 3
; CHECK-NEXT: %cmp = icmp ne i32 %x, 3
}
@ -171,7 +171,7 @@ define i1 @test18(i32 %x) nounwind {
%cmp = icmp eq i32 %and, 0
ret i1 %cmp
; CHECK: @test18
; CHECK-NEXT: %cmp = icmp eq i32 %x, 3
; CHECK-NEXT: %cmp = icmp ne i32 %x, 3
}
define i1 @test19(i32 %x) nounwind {
@ -180,7 +180,7 @@ define i1 @test19(i32 %x) nounwind {
%cmp = icmp eq i32 %and, 8
ret i1 %cmp
; CHECK: @test19
; CHECK-NEXT: %cmp = icmp ne i32 %x, 3
; CHECK-NEXT: %cmp = icmp eq i32 %x, 3
}
define i1 @test20(i32 %x) nounwind {
@ -189,6 +189,6 @@ define i1 @test20(i32 %x) nounwind {
%cmp = icmp ne i32 %and, 0
ret i1 %cmp
; CHECK: @test20
; CHECK-NEXT: %cmp = icmp ne i32 %x, 3
; CHECK-NEXT: %cmp = icmp eq i32 %x, 3
}