[PATCH] D116755: Revert "[CodeGen] Mark fma as const for Android"

Alex Xu (Hello71) via Phabricator via cfe-commits cfe-commits at lists.llvm.org
Thu Jan 6 09:14:50 PST 2022


alxu created this revision.
alxu added a project: clang.
Herald added a subscriber: danielkiss.
alxu requested review of this revision.
Herald added a subscriber: cfe-commits.

This code is intended to give a special exception for platforms which set errno in some math functions but not fma. This does not apply to Android, which does not set errno in any math functions (https://cs.android.com/android/platform/superproject/+/master:bionic/libc/include/math.h;drc=master;l=59). The correct implementation for Android is to set -fno-math-errno by default, which was done in https://reviews.llvm.org/D51068. Therefore, this special exception is no longer needed for Android. Deleting it slightly reduces code complexity, clang executable size, compile time, and test time.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D116755

Files:
  clang/lib/Sema/SemaDecl.cpp
  clang/test/CodeGen/math-builtins.c


Index: clang/test/CodeGen/math-builtins.c
===================================================================
--- clang/test/CodeGen/math-builtins.c
+++ clang/test/CodeGen/math-builtins.c
@@ -1,7 +1,6 @@
 // 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-gnu -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO_GNU
-// RUN: %clang_cc1 -triple x86_64-unknown-unknown-android -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO_ANDROID
 // RUN: %clang_cc1 -triple x86_64-unknown-windows-msvc -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s --check-prefix=HAS_ERRNO_WIN
 
 // Test attributes and codegen of math builtins.
@@ -345,10 +344,6 @@
 // HAS_ERRNO_GNU: declare float @llvm.fma.f32(float, float, float) [[READNONE_INTRINSIC]]
 // HAS_ERRNO_GNU: declare x86_fp80 @llvm.fma.f80(x86_fp80, x86_fp80, x86_fp80) [[READNONE_INTRINSIC]]
 
-// HAS_ERRNO_ANDROID: declare double @llvm.fma.f64(double, double, double) [[READNONE_INTRINSIC:#[0-9]+]]
-// HAS_ERRNO_ANDROID: declare float @llvm.fma.f32(float, float, float) [[READNONE_INTRINSIC]]
-// HAS_ERRNO_ANDROID: declare x86_fp80 @llvm.fma.f80(x86_fp80, x86_fp80, x86_fp80) [[READNONE_INTRINSIC]]
-
 // HAS_ERRNO_WIN: declare double @llvm.fma.f64(double, double, double) [[READNONE_INTRINSIC:#[0-9]+]]
 // HAS_ERRNO_WIN: declare float @llvm.fma.f32(float, float, float) [[READNONE_INTRINSIC]]
 // Long double is just double on win, so no f80 use/declaration.
@@ -696,6 +691,5 @@
 // HAS_ERRNO: attributes [[READNONE]] = { {{.*}}readnone{{.*}} }
 
 // HAS_ERRNO_GNU: attributes [[READNONE_INTRINSIC]] = { {{.*}}readnone{{.*}} }
-// HAS_ERRNO_ANDROID: attributes [[READNONE_INTRINSIC]] = { {{.*}}readnone{{.*}} }
 // HAS_ERRNO_WIN: attributes [[READNONE_INTRINSIC]] = { {{.*}}readnone{{.*}} }
 
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -15191,11 +15191,11 @@
         Context.BuiltinInfo.isConstWithoutErrno(BuiltinID))
       FD->addAttr(ConstAttr::CreateImplicit(Context, FD->getLocation()));
 
-    // We make "fma" on some platforms const because we know it does not set
+    // We make "fma" on GNU or Windows const because we know it does not set
     // errno in those environments even though it could set errno based on the
     // C standard.
     const llvm::Triple &Trip = Context.getTargetInfo().getTriple();
-    if ((Trip.isGNUEnvironment() || Trip.isAndroid() || Trip.isOSMSVCRT()) &&
+    if ((Trip.isGNUEnvironment() || Trip.isOSMSVCRT()) &&
         !FD->hasAttr<ConstAttr>()) {
       switch (BuiltinID) {
       case Builtin::BI__builtin_fma:


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