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[DAGCombine] Don't combine (and (setne X, 0), (setne X, -1)) --> (setuge (add X, 1), 2) for i1

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Reduced from oss-fuzz #4773 test case

llvm-svn: 321455
This commit is contained in:
Simon Pilgrim 2017-12-26 14:48:28 +00:00
parent 345940ba6e
commit e9389ff507
2 changed files with 26 additions and 1 deletions
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3
lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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@ -3577,7 +3577,8 @@ SDValue DAGCombiner::foldLogicOfSetCCs(bool IsAnd, SDValue N0, SDValue N1,
// TODO: What is the 'or' equivalent of this fold?
// (and (setne X, 0), (setne X, -1)) --> (setuge (add X, 1), 2)
if (IsAnd && LL == RL && CC0 == CC1 && IsInteger && CC0 == ISD::SETNE &&
if (IsAnd && LL == RL && CC0 == CC1 && OpVT.getScalarSizeInBits() > 1 &&
IsInteger && CC0 == ISD::SETNE &&
((isNullConstant(LR) && isAllOnesConstant(RR)) ||
(isAllOnesConstant(LR) && isNullConstant(RR)))) {
SDValue One = DAG.getConstant(1, DL, OpVT);

24
test/CodeGen/X86/setcc-combine.ll
View File

@ -183,3 +183,27 @@ define i32 @test_gt_2(<4 x i32> %A, <4 x i32> %B) {
ret i32 %t1
}
; (and (setne X, 0), (setne X, -1)) --> (setuge (add X, 1), 2)
; Don't combine with i1 - out of range constant
define void @test_i1_uge(i1 *%A2) {
; CHECK-LABEL: test_i1_uge:
; CHECK: # %bb.0:
; CHECK-NEXT: movb (%rdi), %al
; CHECK-NEXT: movl %eax, %ecx
; CHECK-NEXT: xorb $1, %cl
; CHECK-NEXT: andb %cl, %al
; CHECK-NEXT: movzbl %al, %eax
; CHECK-NEXT: andl $1, %eax
; CHECK-NEXT: negq %rax
; CHECK-NEXT: andb $1, %cl
; CHECK-NEXT: movb %cl, (%rdi,%rax)
; CHECK-NEXT: retq
%L5 = load i1, i1* %A2
%C3 = icmp ne i1 %L5, true
%C8 = icmp eq i1 %L5, false
%C9 = icmp ugt i1 %C3, %C8
%G3 = getelementptr i1, i1* %A2, i1 %C9
store i1 %C3, i1* %G3
ret void
}