[llvm] 8148c28 - [ConstFolding] fix overzealous assert when converting FP half
Sanjay Patel via llvm-commits
llvm-commits at lists.llvm.org
Sun Aug 7 10:50:27 PDT 2022
Author: Sanjay Patel
Date: 2022-08-07T13:34:51-04:00
New Revision: 8148c28fad4956b6fc785a5cf1d082eda56e1c6a
URL: https://github.com/llvm/llvm-project/commit/8148c28fad4956b6fc785a5cf1d082eda56e1c6a
DIFF: https://github.com/llvm/llvm-project/commit/8148c28fad4956b6fc785a5cf1d082eda56e1c6a.diff
LOG: [ConstFolding] fix overzealous assert when converting FP half
Fixes #56981
Added:
Modified:
llvm/lib/Analysis/ConstantFolding.cpp
llvm/test/Transforms/InstSimplify/ConstProp/convert-from-fp16.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index 38fb50347c301..95ad90b8c765f 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -2360,7 +2360,7 @@ static Constant *ConstantFoldScalarCall1(StringRef Name,
// Conversion is always precise.
(void)status;
- assert(status == APFloat::opOK && !lost &&
+ assert(status != APFloat::opInexact && !lost &&
"Precision lost during fp16 constfolding");
return ConstantFP::get(Ty->getContext(), Val);
diff --git a/llvm/test/Transforms/InstSimplify/ConstProp/convert-from-fp16.ll b/llvm/test/Transforms/InstSimplify/ConstProp/convert-from-fp16.ll
index 86924b945a4e5..2c1b5f0a6a4cb 100644
--- a/llvm/test/Transforms/InstSimplify/ConstProp/convert-from-fp16.ll
+++ b/llvm/test/Transforms/InstSimplify/ConstProp/convert-from-fp16.ll
@@ -1,93 +1,104 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -passes=instsimplify -S < %s | FileCheck %s
; Verify that we don't crash with an assertion failure when constant folding
; a call to intrinsic 'convert.from.fp16' if the return type is not 'float'.
define float @fold_from_fp16_to_fp32() {
-; CHECK-LABEL: @fold_from_fp16_to_fp32
-; CHECK: ret float 0.000000e+00
-entry:
- %0 = call float @llvm.convert.from.fp16.f32(i16 0)
- ret float %0
+; CHECK-LABEL: @fold_from_fp16_to_fp32(
+; CHECK-NEXT: ret float 0.000000e+00
+;
+ %r = call float @llvm.convert.from.fp16.f32(i16 0)
+ ret float %r
}
define double @fold_from_fp16_to_fp64() {
-; CHECK-LABEL: @fold_from_fp16_to_fp64
-; CHECK: ret double 0.000000e+00
-entry:
- %0 = call double @llvm.convert.from.fp16.f64(i16 0)
- ret double %0
+; CHECK-LABEL: @fold_from_fp16_to_fp64(
+; CHECK-NEXT: ret double 0.000000e+00
+;
+ %r = call double @llvm.convert.from.fp16.f64(i16 0)
+ ret double %r
}
define x86_fp80 @fold_from_fp16_to_fp80() {
-; CHECK-LABEL: @fold_from_fp16_to_fp80
-; CHECK: ret x86_fp80 0xK00000000000000000000
-entry:
- %0 = call x86_fp80 @llvm.convert.from.fp16.f80(i16 0)
- ret x86_fp80 %0
+; CHECK-LABEL: @fold_from_fp16_to_fp80(
+; CHECK-NEXT: ret x86_fp80 0xK00000000000000000000
+;
+ %r = call x86_fp80 @llvm.convert.from.fp16.f80(i16 0)
+ ret x86_fp80 %r
}
define fp128 @fold_from_fp16_to_fp128() {
-; CHECK-LABEL: @fold_from_fp16_to_fp128
-; CHECK: ret fp128 0xL00000000000000000000000000000000
-entry:
- %0 = call fp128 @llvm.convert.from.fp16.f128(i16 0)
- ret fp128 %0
+; CHECK-LABEL: @fold_from_fp16_to_fp128(
+; CHECK-NEXT: ret fp128 0xL00000000000000000000000000000000
+;
+ %r = call fp128 @llvm.convert.from.fp16.f128(i16 0)
+ ret fp128 %r
}
define ppc_fp128 @fold_from_fp16_to_ppcfp128() {
-; CHECK-LABEL: @fold_from_fp16_to_ppcfp128
-; CHECK: ret ppc_fp128 0xM00000000000000000000000000000000
-entry:
- %0 = call ppc_fp128 @llvm.convert.from.fp16.ppcf128(i16 0)
- ret ppc_fp128 %0
+; CHECK-LABEL: @fold_from_fp16_to_ppcfp128(
+; CHECK-NEXT: ret ppc_fp128 0xM00000000000000000000000000000000
+;
+ %r = call ppc_fp128 @llvm.convert.from.fp16.ppcf128(i16 0)
+ ret ppc_fp128 %r
}
define float @fold_from_fp16_to_fp32_b() {
-; CHECK-LABEL: @fold_from_fp16_to_fp32_b
-; CHECK: ret float 4.000000e+00
-entry:
- %0 = call i16 @llvm.convert.to.fp16.f64(double 4.0)
- %1 = call float @llvm.convert.from.fp16.f32(i16 %0)
- ret float %1
+; CHECK-LABEL: @fold_from_fp16_to_fp32_b(
+; CHECK-NEXT: ret float 4.000000e+00
+;
+ %a = call i16 @llvm.convert.to.fp16.f64(double 4.0)
+ %r = call float @llvm.convert.from.fp16.f32(i16 %a)
+ ret float %r
}
define double @fold_from_fp16_to_fp64_b() {
-; CHECK-LABEL: @fold_from_fp16_to_fp64_b
-; CHECK: ret double 4.000000e+00
-entry:
- %0 = call i16 @llvm.convert.to.fp16.f64(double 4.0)
- %1 = call double @llvm.convert.from.fp16.f64(i16 %0)
- ret double %1
+; CHECK-LABEL: @fold_from_fp16_to_fp64_b(
+; CHECK-NEXT: ret double 4.000000e+00
+;
+ %a = call i16 @llvm.convert.to.fp16.f64(double 4.0)
+ %r = call double @llvm.convert.from.fp16.f64(i16 %a)
+ ret double %r
}
define x86_fp80 @fold_from_fp16_to_fp80_b() {
-; CHECK-LABEL: @fold_from_fp16_to_fp80_b
-; CHECK: ret x86_fp80 0xK40018000000000000000
-entry:
- %0 = call i16 @llvm.convert.to.fp16.f64(double 4.0)
- %1 = call x86_fp80 @llvm.convert.from.fp16.f80(i16 %0)
- ret x86_fp80 %1
+; CHECK-LABEL: @fold_from_fp16_to_fp80_b(
+; CHECK-NEXT: ret x86_fp80 0xK40018000000000000000
+;
+ %a = call i16 @llvm.convert.to.fp16.f64(double 4.0)
+ %r = call x86_fp80 @llvm.convert.from.fp16.f80(i16 %a)
+ ret x86_fp80 %r
}
define fp128 @fold_from_fp16_to_fp128_b() {
-; CHECK-LABEL: @fold_from_fp16_to_fp128_b
-; CHECK: ret fp128 0xL00000000000000004001000000000000
-entry:
- %0 = call i16 @llvm.convert.to.fp16.f64(double 4.0)
- %1 = call fp128 @llvm.convert.from.fp16.f128(i16 %0)
- ret fp128 %1
+; CHECK-LABEL: @fold_from_fp16_to_fp128_b(
+; CHECK-NEXT: ret fp128 0xL00000000000000004001000000000000
+;
+ %a = call i16 @llvm.convert.to.fp16.f64(double 4.0)
+ %r = call fp128 @llvm.convert.from.fp16.f128(i16 %a)
+ ret fp128 %r
}
define ppc_fp128 @fold_from_fp16_to_ppcfp128_b() {
-; CHECK-LABEL: @fold_from_fp16_to_ppcfp128_b
-; CHECK: ret ppc_fp128 0xM40100000000000000000000000000000
-entry:
- %0 = call i16 @llvm.convert.to.fp16.f64(double 4.0)
- %1 = call ppc_fp128 @llvm.convert.from.fp16.ppcf128(i16 %0)
- ret ppc_fp128 %1
+; CHECK-LABEL: @fold_from_fp16_to_ppcfp128_b(
+; CHECK-NEXT: ret ppc_fp128 0xM40100000000000000000000000000000
+;
+ %a = call i16 @llvm.convert.to.fp16.f64(double 4.0)
+ %r = call ppc_fp128 @llvm.convert.from.fp16.ppcf128(i16 %a)
+ ret ppc_fp128 %r
}
+; This would assert because converting SNAN causes an invalidOp status.
+; PR56981
+
+define float @convert_snan() {
+; CHECK-LABEL: @convert_snan(
+; CHECK-NEXT: ret float 0x7FF8040000000000
+;
+ %r = call float @llvm.convert.from.fp16.f32(i16 31745) ; 0x7c01
+ ret float %r
+}
declare i16 @llvm.convert.to.fp16.f64(double)
declare float @llvm.convert.from.fp16.f32(i16)
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