llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-llvm-analysis Author: Matt Arsenault (arsenm) <details> <summary>Changes</summary> Teach exp handling that positive inputs cannot introduce overflow, and negative inputs cannot introduce underflow. --- Full diff: https://github.com/llvm/llvm-project/pull/173430.diff 2 Files Affected: - (modified) llvm/lib/Analysis/ValueTracking.cpp (+16) - (modified) llvm/test/Transforms/Attributor/nofpclass-exp.ll (+24-24) ``````````diff diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index d866446051fe2..9a3d11eaa38c8 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -5362,6 +5362,22 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts, Known.signBitMustBeZero(); } + if (KnownSrc.cannotBeOrderedLessThanZero()) { + // If the source is positive, and cannot be ~0, this cannot underflow. + Known.knownNot(fcPosZero); + + // Cannot introduce new denormal values. + if (KnownSrc.isKnownNever(fcPosSubnormal)) + Known.knownNot(fcPosSubnormal); + } + + if (KnownSrc.cannotBeOrderedGreaterThanZero()) { + // If the source is negative, and cannot be infinity, this cannot + // overflow to infinity. + if (KnownSrc.isKnownNeverPosInfinity()) + Known.knownNot(fcPosInf); + } + break; } case Intrinsic::fptrunc_round: { diff --git a/llvm/test/Transforms/Attributor/nofpclass-exp.ll b/llvm/test/Transforms/Attributor/nofpclass-exp.ll index ea5c26d101186..941e1d3981af5 100644 --- a/llvm/test/Transforms/Attributor/nofpclass-exp.ll +++ b/llvm/test/Transforms/Attributor/nofpclass-exp.ll @@ -96,10 +96,10 @@ define float @ret_exp_noinf_nonegzero(float nofpclass(inf nzero) %arg0) { } define float @ret_exp_positive_source(i32 %arg) { -; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @ret_exp_positive_source +; CHECK-LABEL: define nofpclass(nan ninf zero sub nnorm) float @ret_exp_positive_source ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR1]] { ; CHECK-NEXT: [[UITOFP:%.*]] = uitofp i32 [[ARG]] to float -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(nan ninf nzero nsub nnorm) float @llvm.exp.f32(float [[UITOFP]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(nan ninf zero sub nnorm) float @llvm.exp.f32(float [[UITOFP]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %uitofp = uitofp i32 %arg to float @@ -211,10 +211,10 @@ define float @ret_exp2_noinf_nonegzero(float nofpclass(inf nzero) %arg0) { } define float @ret_exp2_positive_source(i32 %arg) { -; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @ret_exp2_positive_source +; CHECK-LABEL: define nofpclass(nan ninf zero sub nnorm) float @ret_exp2_positive_source ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR1]] { ; CHECK-NEXT: [[UITOFP:%.*]] = uitofp i32 [[ARG]] to float -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(nan ninf nzero nsub nnorm) float @llvm.exp2.f32(float [[UITOFP]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(nan ninf zero sub nnorm) float @llvm.exp2.f32(float [[UITOFP]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %uitofp = uitofp i32 %arg to float @@ -326,10 +326,10 @@ define float @ret_exp10_noinf_nonegzero(float nofpclass(inf nzero) %arg0) { } define float @ret_exp10_positive_source(i32 %arg) { -; CHECK-LABEL: define nofpclass(nan ninf nzero nsub nnorm) float @ret_exp10_positive_source +; CHECK-LABEL: define nofpclass(nan ninf zero sub nnorm) float @ret_exp10_positive_source ; CHECK-SAME: (i32 [[ARG:%.*]]) #[[ATTR1]] { ; CHECK-NEXT: [[UITOFP:%.*]] = uitofp i32 [[ARG]] to float -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(nan ninf nzero nsub nnorm) float @llvm.exp10.f32(float [[UITOFP]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(nan ninf zero sub nnorm) float @llvm.exp10.f32(float [[UITOFP]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %uitofp = uitofp i32 %arg to float @@ -352,9 +352,9 @@ define float @ret_exp10_unknown_sign(float nofpclass(nan) %arg0, float nofpclass ; Can infer this doesn't return any inf define float @ret_exp_src_known_negative_or_zero_or_nan(float nofpclass(pinf psub pnorm) %arg0) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_src_known_negative_or_zero_or_nan +; CHECK-LABEL: define nofpclass(inf nzero nsub nnorm) float @ret_exp_src_known_negative_or_zero_or_nan ; CHECK-SAME: (float nofpclass(pinf psub pnorm) [[ARG0:%.*]]) #[[ATTR1]] { -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(pinf psub pnorm) [[ARG0]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(inf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(pinf psub pnorm) [[ARG0]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %call = call float @llvm.exp.f32(float %arg0) @@ -363,9 +363,9 @@ define float @ret_exp_src_known_negative_or_zero_or_nan(float nofpclass(pinf psu ; Can infer this doesn't return any inf define float @ret_exp_src_known_negative_nonzero_or_nan(float nofpclass(pinf psub pnorm zero) %arg0) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_src_known_negative_nonzero_or_nan +; CHECK-LABEL: define nofpclass(inf nzero nsub nnorm) float @ret_exp_src_known_negative_nonzero_or_nan ; CHECK-SAME: (float nofpclass(pinf zero psub pnorm) [[ARG0:%.*]]) #[[ATTR1]] { -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(pinf zero psub pnorm) [[ARG0]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(inf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(pinf zero psub pnorm) [[ARG0]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %call = call float @llvm.exp.f32(float %arg0) @@ -373,9 +373,9 @@ define float @ret_exp_src_known_negative_nonzero_or_nan(float nofpclass(pinf psu } define float @ret_exp_src_known_positive_or_zero_or_nan(float nofpclass(ninf nsub nnorm) %arg0) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_src_known_positive_or_zero_or_nan +; CHECK-LABEL: define nofpclass(ninf zero nsub nnorm) float @ret_exp_src_known_positive_or_zero_or_nan ; CHECK-SAME: (float nofpclass(ninf nsub nnorm) [[ARG0:%.*]]) #[[ATTR1]] { -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(ninf nsub nnorm) [[ARG0]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf zero nsub nnorm) float @llvm.exp.f32(float nofpclass(ninf nsub nnorm) [[ARG0]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %call = call float @llvm.exp.f32(float %arg0) @@ -383,9 +383,9 @@ define float @ret_exp_src_known_positive_or_zero_or_nan(float nofpclass(ninf nsu } define float @ret_exp_src_known_positive_non0_or_nan(float nofpclass(ninf nsub nnorm zero) %arg0) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_src_known_positive_non0_or_nan +; CHECK-LABEL: define nofpclass(ninf zero nsub nnorm) float @ret_exp_src_known_positive_non0_or_nan ; CHECK-SAME: (float nofpclass(ninf zero nsub nnorm) [[ARG0:%.*]]) #[[ATTR1]] { -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(ninf zero nsub nnorm) [[ARG0]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf zero nsub nnorm) float @llvm.exp.f32(float nofpclass(ninf zero nsub nnorm) [[ARG0]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %call = call float @llvm.exp.f32(float %arg0) @@ -394,9 +394,9 @@ define float @ret_exp_src_known_positive_non0_or_nan(float nofpclass(ninf nsub n ; Can't underflow to 0, can't be denormal. define float @ret_exp_src_known_positive_non0_nonsub_or_nan(float nofpclass(ninf sub nnorm zero) %arg0) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_src_known_positive_non0_nonsub_or_nan +; CHECK-LABEL: define nofpclass(ninf zero sub nnorm) float @ret_exp_src_known_positive_non0_nonsub_or_nan ; CHECK-SAME: (float nofpclass(ninf zero sub nnorm) [[ARG0:%.*]]) #[[ATTR1]] { -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(ninf zero sub nnorm) [[ARG0]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf zero sub nnorm) float @llvm.exp.f32(float nofpclass(ninf zero sub nnorm) [[ARG0]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %call = call float @llvm.exp.f32(float %arg0) @@ -405,9 +405,9 @@ define float @ret_exp_src_known_positive_non0_nonsub_or_nan(float nofpclass(ninf ; Can't underflow to denormal, but can have an input denormal stay denormal. define float @ret_exp_src_known_positive_or_nan(float nofpclass(ninf nsub nnorm) %arg0) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_src_known_positive_or_nan +; CHECK-LABEL: define nofpclass(ninf zero nsub nnorm) float @ret_exp_src_known_positive_or_nan ; CHECK-SAME: (float nofpclass(ninf nsub nnorm) [[ARG0:%.*]]) #[[ATTR1]] { -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(ninf nsub nnorm) [[ARG0]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf zero nsub nnorm) float @llvm.exp.f32(float nofpclass(ninf nsub nnorm) [[ARG0]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %call = call float @llvm.exp.f32(float %arg0) @@ -415,9 +415,9 @@ define float @ret_exp_src_known_positive_or_nan(float nofpclass(ninf nsub nnorm) } define float @ret_exp_src_known_positive_nonsub_or_nan(float nofpclass(ninf sub nnorm) %arg0) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_src_known_positive_nonsub_or_nan +; CHECK-LABEL: define nofpclass(ninf zero sub nnorm) float @ret_exp_src_known_positive_nonsub_or_nan ; CHECK-SAME: (float nofpclass(ninf sub nnorm) [[ARG0:%.*]]) #[[ATTR1]] { -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float nofpclass(ninf sub nnorm) [[ARG0]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf zero sub nnorm) float @llvm.exp.f32(float nofpclass(ninf sub nnorm) [[ARG0]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %call = call float @llvm.exp.f32(float %arg0) @@ -425,10 +425,10 @@ define float @ret_exp_src_known_positive_nonsub_or_nan(float nofpclass(ninf sub } define float @ret_exp_fabs(float %arg) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_fabs +; CHECK-LABEL: define nofpclass(ninf zero nsub nnorm) float @ret_exp_fabs ; CHECK-SAME: (float [[ARG:%.*]]) #[[ATTR1]] { ; CHECK-NEXT: [[ARG_FABS:%.*]] = call float @llvm.fabs.f32(float [[ARG]]) #[[ATTR2]] -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float [[ARG_FABS]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf zero nsub nnorm) float @llvm.exp.f32(float [[ARG_FABS]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %arg.fabs = call float @llvm.fabs.f32(float %arg) @@ -437,11 +437,11 @@ define float @ret_exp_fabs(float %arg) { } define float @ret_exp_fneg_fabs(float %arg) { -; CHECK-LABEL: define nofpclass(ninf nzero nsub nnorm) float @ret_exp_fneg_fabs +; CHECK-LABEL: define nofpclass(inf nzero nsub nnorm) float @ret_exp_fneg_fabs ; CHECK-SAME: (float [[ARG:%.*]]) #[[ATTR1]] { ; CHECK-NEXT: [[ARG_FABS:%.*]] = call float @llvm.fabs.f32(float [[ARG]]) #[[ATTR2]] ; CHECK-NEXT: [[ARG_NEG_FABS:%.*]] = fneg float [[ARG_FABS]] -; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(ninf nzero nsub nnorm) float @llvm.exp.f32(float [[ARG_NEG_FABS]]) #[[ATTR2]] +; CHECK-NEXT: [[CALL:%.*]] = call nofpclass(inf nzero nsub nnorm) float @llvm.exp.f32(float [[ARG_NEG_FABS]]) #[[ATTR2]] ; CHECK-NEXT: ret float [[CALL]] ; %arg.fabs = call float @llvm.fabs.f32(float %arg) `````````` </details> https://github.com/llvm/llvm-project/pull/173430 _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
