[clang] Fix math-errno issue (PR #66381)
Zahira Ammarguellat via cfe-commits
cfe-commits at lists.llvm.org
Thu Sep 14 14:32:11 PDT 2023
https://github.com/zahiraam updated https://github.com/llvm/llvm-project/pull/66381:
>From 997e3b69ac5c20a9130b957c86c08b16d23af07c Mon Sep 17 00:00:00 2001
From: Zahira Ammarguellat <zahira.ammarguellat at intel.com>
Date: Thu, 14 Sep 2023 06:27:35 -0700
Subject: [PATCH 1/3] Fix math-errno issue
---
clang/lib/CodeGen/CGBuiltin.cpp | 41 +++++++++++++++++++++++++-----
clang/test/CodeGen/math-builtins.c | 2 ++
clang/test/CodeGen/math-libcalls.c | 2 ++
3 files changed, 39 insertions(+), 6 deletions(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 8b19bf85d47a19f..c69ccdb0eb522bf 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -2313,14 +2313,18 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
FD->hasAttr<AsmLabelAttr>() ? 0 : BuiltinID;
bool ErrnoOverriden = false;
+ bool ErrnoOverrideValue = false;
// True if math-errno is overriden via the
// '#pragma float_control(precise, on)'. This pragma disables fast-math,
// which implies math-errno.
if (E->hasStoredFPFeatures()) {
FPOptionsOverride OP = E->getFPFeatures();
- if (OP.hasMathErrnoOverride())
- ErrnoOverriden = OP.getMathErrnoOverride();
+ if (OP.hasMathErrnoOverride()) {
+ ErrnoOverriden = true;
+ ErrnoOverrideValue = OP.getMathErrnoOverride();
+ }
}
+
// True if 'atttibute__((optnone)) is used. This attibute overrides
// fast-math which implies math-errno.
bool OptNone = CurFuncDecl && CurFuncDecl->hasAttr<OptimizeNoneAttr>();
@@ -2329,8 +2333,8 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
// using the '#pragma float_control(precise, off)', and
// attribute opt-none hasn't been seen.
bool ErrnoOverridenToFalseWithOpt =
- !ErrnoOverriden && !OptNone &&
- CGM.getCodeGenOpts().OptimizationLevel != 0;
+ ErrnoOverriden && !ErrnoOverrideValue && !OptNone &&
+ CGM.getCodeGenOpts().OptimizationLevel != 0;
// There are LLVM math intrinsics/instructions corresponding to math library
// functions except the LLVM op will never set errno while the math library
@@ -2339,6 +2343,28 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
// LLVM counterparts if the call is marked 'const' (known to never set errno).
// In case FP exceptions are enabled, the experimental versions of the
// intrinsics model those.
+ bool ConstAlways =
+ getContext().BuiltinInfo.isConst(BuiltinID);
+
+ // There's a special case with the fma builtins where they are always const
+ // if the target environment is GNU or the target is OS is Windows and we're
+ // targeting the MSVCRT.dll environment.
+ switch (BuiltinID) {
+ case Builtin::BI__builtin_fma:
+ case Builtin::BI__builtin_fmaf:
+ case Builtin::BI__builtin_fmal:
+ case Builtin::BIfma:
+ case Builtin::BIfmaf:
+ case Builtin::BIfmal: {
+ auto &Trip = CGM.getTriple();
+ if (Trip.isGNUEnvironment() || Trip.isOSMSVCRT())
+ ConstAlways = true;
+ break;
+ }
+ default:
+ break;
+ }
+
bool ConstWithoutErrnoAndExceptions =
getContext().BuiltinInfo.isConstWithoutErrnoAndExceptions(BuiltinID);
bool ConstWithoutExceptions =
@@ -2362,14 +2388,17 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
bool ConstWithoutErrnoOrExceptions =
ConstWithoutErrnoAndExceptions || ConstWithoutExceptions;
bool GenerateIntrinsics =
- FD->hasAttr<ConstAttr>() && !ErrnoOverriden && !OptNone;
+ (ConstAlways && !OptNone) ||
+ (!getLangOpts().MathErrno && !(ErrnoOverriden && ErrnoOverrideValue) &&
+ !OptNone);
if (!GenerateIntrinsics) {
GenerateIntrinsics =
ConstWithoutErrnoOrExceptions && !ConstWithoutErrnoAndExceptions;
if (!GenerateIntrinsics)
GenerateIntrinsics =
ConstWithoutErrnoOrExceptions &&
- (!getLangOpts().MathErrno && !ErrnoOverriden && !OptNone);
+ (!getLangOpts().MathErrno &&
+ !(ErrnoOverriden && ErrnoOverrideValue) && !OptNone);
if (!GenerateIntrinsics)
GenerateIntrinsics =
ConstWithoutErrnoOrExceptions && ErrnoOverridenToFalseWithOpt;
diff --git a/clang/test/CodeGen/math-builtins.c b/clang/test/CodeGen/math-builtins.c
index 962e311698f5755..554c604219957ca 100644
--- a/clang/test/CodeGen/math-builtins.c
+++ b/clang/test/CodeGen/math-builtins.c
@@ -1,5 +1,7 @@
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -w -S -o - -emit-llvm %s | FileCheck %s -check-prefix=NO__ERRNO
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s -check-prefix=HAS_ERRNO
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -w -S -o - -emit-llvm -disable-llvm-passes -O2 %s | FileCheck %s -check-prefix=NO__ERRNO
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -w -S -o - -emit-llvm -disable-llvm-passes -O2 -fmath-errno %s | FileCheck %s -check-prefix=HAS_ERRNO
// RUN: %clang_cc1 -triple x86_64-unknown-unknown-gnu -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO_GNU
// RUN: %clang_cc1 -triple x86_64-unknown-windows-msvc -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO_WIN
diff --git a/clang/test/CodeGen/math-libcalls.c b/clang/test/CodeGen/math-libcalls.c
index fa8f49d8a2c9ff4..02df4fe5fea6018 100644
--- a/clang/test/CodeGen/math-libcalls.c
+++ b/clang/test/CodeGen/math-libcalls.c
@@ -1,5 +1,7 @@
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -Wno-implicit-function-declaration -w -S -o - -emit-llvm %s | FileCheck %s --check-prefix=NO__ERRNO
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -Wno-implicit-function-declaration -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -Wno-implicit-function-declaration -w -S -o - -emit-llvm -disable-llvm-passes -O2 %s | FileCheck %s --check-prefix=NO__ERRNO
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -Wno-implicit-function-declaration -w -S -o - -emit-llvm -disable-llvm-passes -O2 -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO
// RUN: %clang_cc1 -triple x86_64-unknown-unknown -Wno-implicit-function-declaration -w -S -o - -emit-llvm -ffp-exception-behavior=maytrap %s | FileCheck %s --check-prefix=HAS_MAYTRAP
// RUN: %clang_cc1 -triple x86_64-unknown-unknown-gnu -Wno-implicit-function-declaration -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO_GNU
// RUN: %clang_cc1 -triple x86_64-unknown-windows-msvc -Wno-implicit-function-declaration -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO_WIN
>From 11929053d5fe2ea55ee3faacd7a089de553d857b Mon Sep 17 00:00:00 2001
From: Zahira Ammarguellat <zahira.ammarguellat at intel.com>
Date: Thu, 14 Sep 2023 12:29:14 -0700
Subject: [PATCH 2/3] Fix format
---
clang/lib/CodeGen/CGBuiltin.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index c69ccdb0eb522bf..a97ef5aac994d38 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -2360,7 +2360,7 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
if (Trip.isGNUEnvironment() || Trip.isOSMSVCRT())
ConstAlways = true;
break;
- }
+ }
default:
break;
}
>From a8f414b703adca93d618cca710739ea50f5cb4c0 Mon Sep 17 00:00:00 2001
From: Zahira Ammarguellat <zahira.ammarguellat at intel.com>
Date: Thu, 14 Sep 2023 14:31:59 -0700
Subject: [PATCH 3/3] Added comments
---
clang/lib/CodeGen/CGBuiltin.cpp | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index a97ef5aac994d38..84063807f812cea 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -2314,9 +2314,11 @@ RValue CodeGenFunction::EmitBuiltinExpr(const GlobalDecl GD, unsigned BuiltinID,
bool ErrnoOverriden = false;
bool ErrnoOverrideValue = false;
- // True if math-errno is overriden via the
+ // ErrnoOverriden is true if math-errno is overriden via the
// '#pragma float_control(precise, on)'. This pragma disables fast-math,
// which implies math-errno.
+ // ErrnoOverrideValue is the value to which errno was overriden to (true for
+ // precise on and false otherwise).
if (E->hasStoredFPFeatures()) {
FPOptionsOverride OP = E->getFPFeatures();
if (OP.hasMathErrnoOverride()) {
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