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author | Yingwei Zheng <dtcxzyw2333@gmail.com> | 2024-02-17 23:30:45 +0800 |
---|---|---|
committer | Tom Stellard <tstellar@redhat.com> | 2024-02-19 16:36:53 -0800 |
commit | b845f0662a287912332c89e56f5900037aa7c70f (patch) | |
tree | 43713e126b99b4620b92abd50e3c34d353f8b58b /llvm | |
parent | c5e1885af0426897affc008fab174348eeca7af7 (diff) | |
download | llvm-b845f0662a287912332c89e56f5900037aa7c70f.zip llvm-b845f0662a287912332c89e56f5900037aa7c70f.tar.gz llvm-b845f0662a287912332c89e56f5900037aa7c70f.tar.bz2 |
[ValueTracking] Fix computeKnownFPClass for fpext (#81972)
This patch adds the missing `subnormal -> normal` part for `fpext` in
`computeKnownFPClass`.
Fixes the miscompilation reported by
https://github.com/llvm/llvm-project/pull/80941#issuecomment-1947302100.
(cherry picked from commit a5865c3c3dbbd17ae12ecc1c297fe1fc2605df52)
Diffstat (limited to 'llvm')
-rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 7 | ||||
-rw-r--r-- | llvm/test/Transforms/Attributor/nofpclass-fpext.ll | 34 | ||||
-rw-r--r-- | llvm/test/Transforms/InstCombine/pr80941.ll | 32 |
3 files changed, 70 insertions, 3 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 5d6c346..412115e 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -5083,8 +5083,13 @@ void computeKnownFPClass(const Value *V, const APInt &DemandedElts, Op->getOperand(0)->getType()->getScalarType()->getFltSemantics(); // All subnormal inputs should be in the normal range in the result type. - if (APFloat::isRepresentableAsNormalIn(SrcTy, DstTy)) + if (APFloat::isRepresentableAsNormalIn(SrcTy, DstTy)) { + if (Known.KnownFPClasses & fcPosSubnormal) + Known.KnownFPClasses |= fcPosNormal; + if (Known.KnownFPClasses & fcNegSubnormal) + Known.KnownFPClasses |= fcNegNormal; Known.knownNot(fcSubnormal); + } // Sign bit of a nan isn't guaranteed. if (!Known.isKnownNeverNaN()) diff --git a/llvm/test/Transforms/Attributor/nofpclass-fpext.ll b/llvm/test/Transforms/Attributor/nofpclass-fpext.ll index 0ba1141..ee36f94 100644 --- a/llvm/test/Transforms/Attributor/nofpclass-fpext.ll +++ b/llvm/test/Transforms/Attributor/nofpclass-fpext.ll @@ -142,7 +142,7 @@ define double @ret_fpext_f32_to_f64_nosub(float nofpclass(sub) %arg0) { } define double @ret_fpext_f32_to_f64_nonorm(float nofpclass(norm) %arg0) { -; CHECK-LABEL: define nofpclass(sub norm) double @ret_fpext_f32_to_f64_nonorm +; CHECK-LABEL: define nofpclass(sub) double @ret_fpext_f32_to_f64_nonorm ; CHECK-SAME: (float nofpclass(sub norm) [[ARG0:%.*]]) #[[ATTR0]] { ; CHECK-NEXT: [[EXT:%.*]] = fpext float [[ARG0]] to double ; CHECK-NEXT: ret double [[EXT]] @@ -482,7 +482,37 @@ define double @ret_fpext_bf16_f64_nosub(bfloat nofpclass(sub) %arg0) { } define double @ret_fpext_bf16_f64_nonorm(bfloat nofpclass(norm) %arg0) { -; CHECK-LABEL: define nofpclass(sub norm) double @ret_fpext_bf16_f64_nonorm +; CHECK-LABEL: define nofpclass(sub) double @ret_fpext_bf16_f64_nonorm +; CHECK-SAME: (bfloat nofpclass(sub norm) [[ARG0:%.*]]) #[[ATTR0]] { +; CHECK-NEXT: [[EXT:%.*]] = fpext bfloat [[ARG0]] to double +; CHECK-NEXT: ret double [[EXT]] +; + %ext = fpext bfloat %arg0 to double + ret double %ext +} + +define double @ret_fpext_bf16_f64_nonorm_psub(bfloat nofpclass(norm psub) %arg0) { +; CHECK-LABEL: define nofpclass(sub pnorm) double @ret_fpext_bf16_f64_nonorm_psub +; CHECK-SAME: (bfloat nofpclass(sub norm) [[ARG0:%.*]]) #[[ATTR0]] { +; CHECK-NEXT: [[EXT:%.*]] = fpext bfloat [[ARG0]] to double +; CHECK-NEXT: ret double [[EXT]] +; + %ext = fpext bfloat %arg0 to double + ret double %ext +} + +define double @ret_fpext_bf16_f64_nonorm_nsub(bfloat nofpclass(norm nsub) %arg0) { +; CHECK-LABEL: define nofpclass(sub nnorm) double @ret_fpext_bf16_f64_nonorm_nsub +; CHECK-SAME: (bfloat nofpclass(sub norm) [[ARG0:%.*]]) #[[ATTR0]] { +; CHECK-NEXT: [[EXT:%.*]] = fpext bfloat [[ARG0]] to double +; CHECK-NEXT: ret double [[EXT]] +; + %ext = fpext bfloat %arg0 to double + ret double %ext +} + +define double @ret_fpext_bf16_f64_nonorm_sub(bfloat nofpclass(norm sub) %arg0) { +; CHECK-LABEL: define nofpclass(sub norm) double @ret_fpext_bf16_f64_nonorm_sub ; CHECK-SAME: (bfloat nofpclass(sub norm) [[ARG0:%.*]]) #[[ATTR0]] { ; CHECK-NEXT: [[EXT:%.*]] = fpext bfloat [[ARG0]] to double ; CHECK-NEXT: ret double [[EXT]] diff --git a/llvm/test/Transforms/InstCombine/pr80941.ll b/llvm/test/Transforms/InstCombine/pr80941.ll new file mode 100644 index 0000000..95242b1 --- /dev/null +++ b/llvm/test/Transforms/InstCombine/pr80941.ll @@ -0,0 +1,32 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4 +; RUN: opt -S -passes=instcombine < %s | FileCheck %s + +define float @pr80941(float %arg) { +; CHECK-LABEL: define float @pr80941( +; CHECK-SAME: float [[ARG:%.*]]) { +; CHECK-NEXT: entry: +; CHECK-NEXT: [[COND:%.*]] = tail call i1 @llvm.is.fpclass.f32(float [[ARG]], i32 144) +; CHECK-NEXT: br i1 [[COND]], label [[IF_THEN:%.*]], label [[IF_EXIT:%.*]] +; CHECK: if.then: +; CHECK-NEXT: [[FPEXT:%.*]] = fpext float [[ARG]] to double +; CHECK-NEXT: [[SIGN:%.*]] = call double @llvm.copysign.f64(double 0.000000e+00, double [[FPEXT]]) +; CHECK-NEXT: [[FPTRUNC:%.*]] = fptrunc double [[SIGN]] to float +; CHECK-NEXT: br label [[IF_EXIT]] +; CHECK: if.exit: +; CHECK-NEXT: [[RET:%.*]] = phi float [ [[FPTRUNC]], [[IF_THEN]] ], [ [[ARG]], [[ENTRY:%.*]] ] +; CHECK-NEXT: ret float [[RET]] +; +entry: + %cond = tail call i1 @llvm.is.fpclass.f32(float %arg, i32 144) + br i1 %cond, label %if.then, label %if.exit + +if.then: + %fpext = fpext float %arg to double + %sign = call double @llvm.copysign.f64(double 0.000000e+00, double %fpext) + %fptrunc = fptrunc double %sign to float + br label %if.exit + +if.exit: + %ret = phi float [ %fptrunc, %if.then ], [ %arg, %entry ] + ret float %ret +} |