[llvm] 77e3fea - ValueTracking: Improve trunc handling in computeKnownFPClass
Matt Arsenault via llvm-commits
llvm-commits at lists.llvm.org
Wed Apr 26 02:21:11 PDT 2023
Author: Matt Arsenault
Date: 2023-04-26T05:20:56-04:00
New Revision: 77e3fea02bf27c49ce9ebe7452aab43cc1235f8b
URL: https://github.com/llvm/llvm-project/commit/77e3fea02bf27c49ce9ebe7452aab43cc1235f8b
DIFF: https://github.com/llvm/llvm-project/commit/77e3fea02bf27c49ce9ebe7452aab43cc1235f8b.diff
LOG: ValueTracking: Improve trunc handling in computeKnownFPClass
Added:
Modified:
llvm/include/llvm/Analysis/ValueTracking.h
llvm/lib/Analysis/ValueTracking.cpp
llvm/test/Transforms/Attributor/nofpclass-trunc.ll
Removed:
################################################################################
diff --git a/llvm/include/llvm/Analysis/ValueTracking.h b/llvm/include/llvm/Analysis/ValueTracking.h
index 0947dbb7b688..dc68691cae7c 100644
--- a/llvm/include/llvm/Analysis/ValueTracking.h
+++ b/llvm/include/llvm/Analysis/ValueTracking.h
@@ -238,6 +238,10 @@ struct KnownFPClass {
/// definitely set or false if the sign bit is definitely unset.
std::optional<bool> SignBit;
+ /// Return true if it's known this can never be one of the mask entries.
+ bool isKnownNever(FPClassTest Mask) const {
+ return (KnownFPClasses & Mask) == fcNone;
+ }
bool isUnknown() const {
return KnownFPClasses == fcAllFlags && !SignBit;
@@ -245,33 +249,43 @@ struct KnownFPClass {
/// Return true if it's known this can never be a nan.
bool isKnownNeverNaN() const {
- return (KnownFPClasses & fcNan) == fcNone;
+ return isKnownNever(fcNan);
}
/// Return true if it's known this can never be an infinity.
bool isKnownNeverInfinity() const {
- return (KnownFPClasses & fcInf) == fcNone;
+ return isKnownNever(fcInf);
}
/// Return true if it's known this can never be +infinity.
bool isKnownNeverPosInfinity() const {
- return (KnownFPClasses & fcPosInf) == fcNone;
+ return isKnownNever(fcPosInf);
}
/// Return true if it's known this can never be -infinity.
bool isKnownNeverNegInfinity() const {
- return (KnownFPClasses & fcNegInf) == fcNone;
+ return isKnownNever(fcNegInf);
}
/// Return true if it's known this can never be a subnormal
bool isKnownNeverSubnormal() const {
- return (KnownFPClasses & fcSubnormal) == fcNone;
+ return isKnownNever(fcSubnormal);
+ }
+
+ /// Return true if it's known this can never be a negativesubnormal
+ bool isKnownNeverNegSubnormal() const {
+ return isKnownNever(fcNegSubnormal);
}
/// Return true if it's known this can never be a zero. This means a literal
/// [+-]0, and does not include denormal inputs implicitly treated as [+-]0.
bool isKnownNeverZero() const {
- return (KnownFPClasses & fcZero) == fcNone;
+ return isKnownNever(fcZero);
+ }
+
+ /// Return true if it's known this can never be a literal negative zero.
+ bool isKnownNeverNegZero() const {
+ return isKnownNever(fcNegZero);
}
/// Return true if it's know this can never be interpreted as a zero. This
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index fa5c21404b43..249b22873c78 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4620,8 +4620,13 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
}
case Intrinsic::trunc: {
KnownFPClass KnownSrc;
- computeKnownFPClass(II->getArgOperand(0), DemandedElts,
- InterestedClasses, KnownSrc, Depth + 1, Q, TLI);
+
+ FPClassTest InterestedSrcs = InterestedClasses;
+ if (InterestedClasses & fcZero)
+ InterestedClasses |= fcNormal | fcSubnormal;
+
+ computeKnownFPClass(II->getArgOperand(0), DemandedElts, InterestedSrcs,
+ KnownSrc, Depth + 1, Q, TLI);
// Integer results cannot be subnormal.
Known.knownNot(fcSubnormal);
@@ -4635,6 +4640,21 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
// Non-constrained intrinsics do not guarantee signaling nan quieting.
if (KnownSrc.isKnownNeverNaN())
Known.knownNot(fcNan);
+
+ if (KnownSrc.isKnownNever(fcPosNormal))
+ Known.knownNot(fcPosNormal);
+
+ if (KnownSrc.isKnownNever(fcNegNormal))
+ Known.knownNot(fcNegNormal);
+
+ if (KnownSrc.isKnownNever(fcPosZero | fcPosSubnormal | fcPosNormal))
+ Known.knownNot(fcPosZero);
+
+ if (KnownSrc.isKnownNever(fcNegZero | fcNegSubnormal | fcNegNormal))
+ Known.knownNot(fcNegZero);
+
+ // Sign should be preserved
+ Known.SignBit = KnownSrc.SignBit;
break;
}
case Intrinsic::exp:
@@ -4675,7 +4695,7 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts,
if ((InterestedClasses & fcNegInf) != fcNone)
InterestedSrcs |= fcZero | fcSubnormal;
if ((InterestedClasses & fcNan) != fcNone)
- InterestedSrcs |= fcNan | KnownFPClass::OrderedLessThanZeroMask;
+ InterestedSrcs |= fcNan | (fcNegative & ~fcNan);
KnownFPClass KnownSrc;
computeKnownFPClass(II->getArgOperand(0), DemandedElts, InterestedSrcs,
diff --git a/llvm/test/Transforms/Attributor/nofpclass-trunc.ll b/llvm/test/Transforms/Attributor/nofpclass-trunc.ll
index eda3bdf379af..63c9d2f066c7 100644
--- a/llvm/test/Transforms/Attributor/nofpclass-trunc.ll
+++ b/llvm/test/Transforms/Attributor/nofpclass-trunc.ll
@@ -105,9 +105,9 @@ define float @ret_trunc_nonzero(float nofpclass(nzero) %arg0) {
}
define float @ret_trunc_nonorm(float nofpclass(norm) %arg0) {
-; CHECK-LABEL: define nofpclass(sub) float @ret_trunc_nonorm
+; CHECK-LABEL: define nofpclass(sub norm) float @ret_trunc_nonorm
; CHECK-SAME: (float nofpclass(norm) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub norm) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
; CHECK-NEXT: ret float [[CALL]]
;
%call = call float @llvm.trunc.f32(float %arg0)
@@ -115,9 +115,9 @@ define float @ret_trunc_nonorm(float nofpclass(norm) %arg0) {
}
define float @ret_trunc_nonnorm(float nofpclass(nnorm) %arg0) {
-; CHECK-LABEL: define nofpclass(sub) float @ret_trunc_nonnorm
+; CHECK-LABEL: define nofpclass(sub nnorm) float @ret_trunc_nonnorm
; CHECK-SAME: (float nofpclass(nnorm) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub nnorm) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
; CHECK-NEXT: ret float [[CALL]]
;
%call = call float @llvm.trunc.f32(float %arg0)
@@ -125,9 +125,9 @@ define float @ret_trunc_nonnorm(float nofpclass(nnorm) %arg0) {
}
define float @ret_trunc_nopnorm(float nofpclass(pnorm) %arg0) {
-; CHECK-LABEL: define nofpclass(sub) float @ret_trunc_nopnorm
+; CHECK-LABEL: define nofpclass(sub pnorm) float @ret_trunc_nopnorm
; CHECK-SAME: (float nofpclass(pnorm) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub pnorm) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
; CHECK-NEXT: ret float [[CALL]]
;
%call = call float @llvm.trunc.f32(float %arg0)
@@ -155,9 +155,9 @@ define float @ret_trunc_nopsub(float nofpclass(psub) %arg0) {
}
define float @ret_trunc_nonorm_nosub(float nofpclass(norm sub) %arg0) {
-; CHECK-LABEL: define nofpclass(sub) float @ret_trunc_nonorm_nosub
+; CHECK-LABEL: define nofpclass(sub norm) float @ret_trunc_nonorm_nosub
; CHECK-SAME: (float nofpclass(sub norm) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub norm) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
; CHECK-NEXT: ret float [[CALL]]
;
%call = call float @llvm.trunc.f32(float %arg0)
@@ -165,9 +165,9 @@ define float @ret_trunc_nonorm_nosub(float nofpclass(norm sub) %arg0) {
}
define float @ret_trunc_nopnorm_nopsub(float nofpclass(pnorm psub) %arg0) {
-; CHECK-LABEL: define nofpclass(sub) float @ret_trunc_nopnorm_nopsub
+; CHECK-LABEL: define nofpclass(sub pnorm) float @ret_trunc_nopnorm_nopsub
; CHECK-SAME: (float nofpclass(psub pnorm) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub pnorm) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
; CHECK-NEXT: ret float [[CALL]]
;
%call = call float @llvm.trunc.f32(float %arg0)
@@ -175,9 +175,9 @@ define float @ret_trunc_nopnorm_nopsub(float nofpclass(pnorm psub) %arg0) {
}
define float @ret_trunc_nonnorm_nonsub(float nofpclass(nnorm nsub) %arg0) {
-; CHECK-LABEL: define nofpclass(sub) float @ret_trunc_nonnorm_nonsub
+; CHECK-LABEL: define nofpclass(sub nnorm) float @ret_trunc_nonnorm_nonsub
; CHECK-SAME: (float nofpclass(nsub nnorm) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub nnorm) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
; CHECK-NEXT: ret float [[CALL]]
;
%call = call float @llvm.trunc.f32(float %arg0)
@@ -185,9 +185,9 @@ define float @ret_trunc_nonnorm_nonsub(float nofpclass(nnorm nsub) %arg0) {
}
define float @ret_trunc_nopnorm_nonsub(float nofpclass(pnorm nsub) %arg0) {
-; CHECK-LABEL: define nofpclass(sub) float @ret_trunc_nopnorm_nonsub
+; CHECK-LABEL: define nofpclass(sub pnorm) float @ret_trunc_nopnorm_nonsub
; CHECK-SAME: (float nofpclass(nsub pnorm) [[ARG0:%.*]]) #[[ATTR1]] {
-; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
+; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(sub pnorm) float @llvm.trunc.f32(float [[ARG0]]) #[[ATTR2]]
; CHECK-NEXT: ret float [[CALL]]
;
%call = call float @llvm.trunc.f32(float %arg0)
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