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[InstCombine] Fix FMF propagation in foldFCmpFSubIntoFCmp #161539

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Merged
merged 2 commits into from
Oct 2, 2025
Merged

[InstCombine] Fix FMF propagation in foldFCmpFSubIntoFCmp #161539

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fe70756
[InstCombine] Add pre-commit tests. NFC.
dtcxzyw Oct 1, 2025
ba95bd5
[InstCombine] Fix FMF propagation in `foldFCmpFSubIntoFCmp`
dtcxzyw Oct 1, 2025
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3 changes: 3 additions & 0 deletions llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -8527,6 +8527,9 @@ static Instruction *foldFCmpFSubIntoFCmp(FCmpInst &I, Instruction *LHSI,
DenormalMode::getIEEE()) {
CI.replaceOperand(I, 0, X);
CI.replaceOperand(I, 1, Y);
I.setHasNoInfs(LHSI->hasNoInfs());
if (LHSI->hasNoNaNs())
I.setHasNoNaNs(true);
return &I;
}
break;
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40 changes: 40 additions & 0 deletions llvm/test/Transforms/InstCombine/fcmp.ll
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Expand Up @@ -1812,6 +1812,46 @@ define i1 @fcmp_ule_fsub_const(float %x, float %y) {
ret i1 %cmp
}

define i1 @fcmp_ninf_ule_fsub_const(float %x, float %y) {
; CHECK-LABEL: @fcmp_ninf_ule_fsub_const(
; CHECK-NEXT: [[CMP:%.*]] = fcmp ule float [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[CMP]]
;
%fs = fsub float %x, %y
%cmp = fcmp ninf ule float %fs, 0.000000e+00
ret i1 %cmp
}

define i1 @fcmp_nnan_ule_fsub_const(float %x, float %y) {
; CHECK-LABEL: @fcmp_nnan_ule_fsub_const(
; CHECK-NEXT: [[CMP:%.*]] = fcmp nnan ule float [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[CMP]]
;
%fs = fsub float %x, %y
%cmp = fcmp nnan ule float %fs, 0.000000e+00
ret i1 %cmp
}

define i1 @fcmp_ule_fsub_ninf_const(float %x, float %y) {
; CHECK-LABEL: @fcmp_ule_fsub_ninf_const(
; CHECK-NEXT: [[CMP:%.*]] = fcmp ninf ule float [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[CMP]]
;
%fs = fsub ninf float %x, %y
%cmp = fcmp ule float %fs, 0.000000e+00
ret i1 %cmp
}

define i1 @fcmp_ule_fsub_nnan_const(float %x, float %y) {
; CHECK-LABEL: @fcmp_ule_fsub_nnan_const(
; CHECK-NEXT: [[CMP:%.*]] = fcmp nnan ule float [[X:%.*]], [[Y:%.*]]
; CHECK-NEXT: ret i1 [[CMP]]
;
%fs = fsub nnan float %x, %y
%cmp = fcmp ule float %fs, 0.000000e+00
ret i1 %cmp
}

define i1 @fcmp_ugt_fsub_const(float %x, float %y) {
; CHECK-LABEL: @fcmp_ugt_fsub_const(
; CHECK-NEXT: [[FS:%.*]] = fsub float [[X:%.*]], [[Y:%.*]]
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