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[ConstantFold] Fold ilogb and ilogbf when the input parameter is a constant value. #113014

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Merged
merged 6 commits into from
Oct 20, 2024
Merged

[ConstantFold] Fold ilogb and ilogbf when the input parameter is a constant value. #113014

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constant fold ilogb
c8ef Oct 19, 2024
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Merge branch 'main' into ilogb
c8ef Oct 19, 2024
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address review comments
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try deleting check
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Revert "try deleting check"
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Merge branch 'main' into ilogb
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11 changes: 7 additions & 4 deletions llvm/lib/Analysis/ConstantFolding.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1677,6 +1677,8 @@ bool llvm::canConstantFoldCallTo(const CallBase *Call, const Function *F) {
return Name == "fabs" || Name == "fabsf" ||
Name == "floor" || Name == "floorf" ||
Name == "fmod" || Name == "fmodf";
case 'i':
return Name == "ilogb" || Name == "ilogbf";
case 'l':
return Name == "log" || Name == "logf" || Name == "logl" ||
Name == "log2" || Name == "log2f" || Name == "log10" ||
Expand Down Expand Up @@ -2131,11 +2133,7 @@ static Constant *ConstantFoldScalarCall1(StringRef Name,
}
#endif

if (!Ty->isHalfTy() && !Ty->isFloatTy() && !Ty->isDoubleTy())
return nullptr;

// Use internal versions of these intrinsics.

if (IntrinsicID == Intrinsic::nearbyint || IntrinsicID == Intrinsic::rint) {
U.roundToIntegral(APFloat::rmNearestTiesToEven);
return ConstantFP::get(Ty->getContext(), U);
Expand Down Expand Up @@ -2391,6 +2389,11 @@ static Constant *ConstantFoldScalarCall1(StringRef Name,
// TODO: What about hosts that lack a C99 library?
return ConstantFoldFP(log10, APF, Ty);
break;
case LibFunc_ilogb:
case LibFunc_ilogbf:
if (!APF.isZero() && TLI->has(Func))
return ConstantInt::get(Ty, ilogb(APF), true);
break;
case LibFunc_logb:
case LibFunc_logbf:
if (!APF.isZero() && TLI->has(Func))
Expand Down
203 changes: 203 additions & 0 deletions llvm/test/Transforms/InstCombine/ilogb.ll
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@@ -0,0 +1,203 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt < %s -passes=instcombine -S | FileCheck %s

define i32 @ilogbf_const1() {
; CHECK-LABEL: define i32 @ilogbf_const1() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float 7.000000e+00)
; CHECK-NEXT: ret i32 2
;
%r = call i32 @ilogbf(float 7.000000e+00)
ret i32 %r
}

define i32 @ilogb_const1() {
; CHECK-LABEL: define i32 @ilogb_const1() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double -7.000000e+00)
; CHECK-NEXT: ret i32 2
;
%r = call i32 @ilogb(double -7.000000e+00)
ret i32 %r
}

define i32 @ilogbf_const2() {
; CHECK-LABEL: define i32 @ilogbf_const2() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float 5.000000e-01)
; CHECK-NEXT: ret i32 -1
;
%r = call i32 @ilogbf(float 5.000000e-01)
ret i32 %r
}

define i32 @ilogb_const2() {
; CHECK-LABEL: define i32 @ilogb_const2() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double -5.000000e-01)
; CHECK-NEXT: ret i32 -1
;
%r = call i32 @ilogb(double -5.000000e-01)
ret i32 %r
}

define i32 @ilogbf_zero() {
; CHECK-LABEL: define i32 @ilogbf_zero() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float 0.000000e+00)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float 0.000000e+00)
ret i32 %r
}

define i32 @ilogb_zero() {
; CHECK-LABEL: define i32 @ilogb_zero() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double 0.000000e+00)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double 0.000000e+00)
ret i32 %r
}

define i32 @ilogbf_neg_zero() {
; CHECK-LABEL: define i32 @ilogbf_neg_zero() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float -0.000000e+00)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float -0.000000e+00)
ret i32 %r
}

define i32 @ilogb_neg_zero() {
; CHECK-LABEL: define i32 @ilogb_neg_zero() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double -0.000000e+00)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double -0.000000e+00)
ret i32 %r
}

define i32 @ilogbf_inf() {
; CHECK-LABEL: define i32 @ilogbf_inf() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float 0x7FF0000000000000)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float 0x7FF0000000000000)
ret i32 %r
}

define i32 @ilogb_inf() {
; CHECK-LABEL: define i32 @ilogb_inf() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double 0x7FF0000000000000)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double 0x7FF0000000000000)
ret i32 %r
}

define i32 @ilogbf_nan() {
; CHECK-LABEL: define i32 @ilogbf_nan() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float 0x7FF8000000000000)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float 0x7FF8000000000000)
ret i32 %r
}

define i32 @ilogb_nan() {
; CHECK-LABEL: define i32 @ilogb_nan() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double 0x7FF8000000000000)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double 0x7FF8000000000000)
ret i32 %r
}

define i32 @ilogbf_zero_readnone() {
; CHECK-LABEL: define i32 @ilogbf_zero_readnone() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float 0.000000e+00) #[[ATTR0:[0-9]+]]
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float 0.000000e+00) readnone
ret i32 %r
}

define i32 @ilogb_zero_readnone() {
; CHECK-LABEL: define i32 @ilogb_zero_readnone() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double 0.000000e+00) #[[ATTR0]]
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double 0.000000e+00) readnone
ret i32 %r
}

define i32 @ilogbf_neg_zero_readnone() {
; CHECK-LABEL: define i32 @ilogbf_neg_zero_readnone() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float -0.000000e+00) #[[ATTR0]]
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float -0.000000e+00) readnone
ret i32 %r
}

define i32 @ilogb_neg_zero_readnone() {
; CHECK-LABEL: define i32 @ilogb_neg_zero_readnone() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double -0.000000e+00) #[[ATTR0]]
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double -0.000000e+00) readnone
ret i32 %r
}

define i32 @ilogbf_inf_readnone() {
; CHECK-LABEL: define i32 @ilogbf_inf_readnone() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float 0x7FF0000000000000) #[[ATTR0]]
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float 0x7FF0000000000000) readnone
ret i32 %r
}

define i32 @ilogb_inf_readnone() {
; CHECK-LABEL: define i32 @ilogb_inf_readnone() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double 0x7FF0000000000000) #[[ATTR0]]
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double 0x7FF0000000000000) readnone
ret i32 %r
}

define i32 @ilogbf_nan_readnone() {
; CHECK-LABEL: define i32 @ilogbf_nan_readnone() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float 0x7FF8000000000000) #[[ATTR0]]
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float 0x7FF8000000000000) readnone
ret i32 %r
}

define i32 @ilogb_nan_readnone() {
; CHECK-LABEL: define i32 @ilogb_nan_readnone() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double 0x7FF8000000000000) #[[ATTR0]]
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double 0x7FF8000000000000) readnone
ret i32 %r
}

define i32 @ilogbf_poison() {
; CHECK-LABEL: define i32 @ilogbf_poison() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogbf(float poison)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogbf(float poison)
ret i32 %r
}

define i32 @ilogb_poison() {
; CHECK-LABEL: define i32 @ilogb_poison() {
; CHECK-NEXT: [[R:%.*]] = call i32 @ilogb(double poison)
; CHECK-NEXT: ret i32 [[R]]
;
%r = call i32 @ilogb(double poison)
ret i32 %r
}

declare i32 @ilogbf(float)
declare i32 @ilogb(double)
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