[clang] eab2a06 - Revert "Reland "[X86] Support `_Float16` on SSE2 and up""

Ben Langmuir via cfe-commits cfe-commits at lists.llvm.org
Tue Jun 28 10:59:46 PDT 2022


Author: Ben Langmuir
Date: 2022-06-28T10:59:03-07:00
New Revision: eab2a06f0fde51eee6b1526bd301d60c4cc9b050

URL: https://github.com/llvm/llvm-project/commit/eab2a06f0fde51eee6b1526bd301d60c4cc9b050
DIFF: https://github.com/llvm/llvm-project/commit/eab2a06f0fde51eee6b1526bd301d60c4cc9b050.diff

LOG: Revert "Reland "[X86] Support `_Float16` on SSE2 and up""

Broke compiler-rt on Darwin: https://green.lab.llvm.org/green/job/clang-stage1-RA/29920/

This reverts commit 527ef8ca981e88a35758c0e4143be6853ea26dfc.

Added: 
    clang/test/CodeGen/X86/avx512fp16-complex.c

Modified: 
    clang/docs/LanguageExtensions.rst
    clang/docs/ReleaseNotes.rst
    clang/lib/Basic/Targets/X86.cpp
    clang/test/Sema/Float16.c
    clang/test/Sema/conversion-target-dep.c
    clang/test/SemaCXX/Float16.cpp
    compiler-rt/test/builtins/CMakeLists.txt

Removed: 
    clang/test/CodeGen/X86/Float16-arithmetic.c
    clang/test/CodeGen/X86/Float16-complex.c


################################################################################
diff  --git a/clang/docs/LanguageExtensions.rst b/clang/docs/LanguageExtensions.rst
index 1bac2aee84bd9..af697fafd8c41 100644
--- a/clang/docs/LanguageExtensions.rst
+++ b/clang/docs/LanguageExtensions.rst
@@ -743,13 +743,7 @@ targets pending ABI standardization:
 * 64-bit ARM (AArch64)
 * AMDGPU
 * SPIR
-* X86 (see below)
-
-On X86 targets, ``_Float16`` is supported as long as SSE2 is available, which
-includes all 64-bit and all recent 32-bit processors. When the target supports
-AVX512-FP16, ``_Float16`` arithmetic is performed using that native support.
-Otherwise, ``_Float16`` arithmetic is performed by promoting to ``float``,
-performing the operation, and then truncating to ``_Float16``.
+* X86 (Only available under feature AVX512-FP16)
 
 ``_Float16`` will be supported on more targets as they define ABIs for it.
 

diff  --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 733f10a7e4d1a..3e29987ad2631 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -514,9 +514,6 @@ X86 Support in Clang
 
 - Support ``-mharden-sls=[none|all|return|indirect-jmp]`` for straight-line
   speculation hardening.
-- Support for the ``_Float16`` type has been added for all targets with SSE2.
-  When AVX512-FP16 is not available, arithmetic on ``_Float16`` is emulated
-  using ``float``.
 
 DWARF Support in Clang
 ----------------------

diff  --git a/clang/lib/Basic/Targets/X86.cpp b/clang/lib/Basic/Targets/X86.cpp
index 0b3d87837ef6a..b83b3517ddf90 100644
--- a/clang/lib/Basic/Targets/X86.cpp
+++ b/clang/lib/Basic/Targets/X86.cpp
@@ -239,6 +239,7 @@ bool X86TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
       HasAVX512ER = true;
     } else if (Feature == "+avx512fp16") {
       HasAVX512FP16 = true;
+      HasFloat16 = true;
     } else if (Feature == "+avx512pf") {
       HasAVX512PF = true;
     } else if (Feature == "+avx512dq") {
@@ -354,9 +355,6 @@ bool X86TargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
                            .Default(NoSSE);
     SSELevel = std::max(SSELevel, Level);
 
-    // Turn on _float16 for x86 (feature sse2)
-    HasFloat16 = SSELevel >= SSE2;
-
     MMX3DNowEnum ThreeDNowLevel = llvm::StringSwitch<MMX3DNowEnum>(Feature)
                                       .Case("+3dnowa", AMD3DNowAthlon)
                                       .Case("+3dnow", AMD3DNow)

diff  --git a/clang/test/CodeGen/X86/Float16-arithmetic.c b/clang/test/CodeGen/X86/Float16-arithmetic.c
deleted file mode 100644
index 726da22a22b08..0000000000000
--- a/clang/test/CodeGen/X86/Float16-arithmetic.c
+++ /dev/null
@@ -1,29 +0,0 @@
-// RUN: %clang_cc1 -triple  x86_64-unknown-unknown \
-// RUN: -emit-llvm -o - %s  | FileCheck %s --check-prefixes=CHECK
-
-// CHECK-NOT: fpext
-// CHECK-NOT: fptrunc
-
-_Float16 add1(_Float16 a, _Float16 b) {
-  return a + b;
-}
-
-_Float16 add2(_Float16 a, _Float16 b, _Float16 c) {
-  return a + b + c;
-}
-
-_Float16 div(_Float16 a, _Float16 b) {
-  return a / b;
-}
-
-_Float16 mul(_Float16 a, _Float16 b) {
-  return a * b;
-}
-
-_Float16 add_and_mul1(_Float16 a, _Float16 b, _Float16 c, _Float16 d) {
-  return a * b + c * d;
-}
-
-_Float16 add_and_mul2(_Float16 a, _Float16 b, _Float16 c, _Float16 d) {
-  return (a - 6 * b) + c;
-}

diff  --git a/clang/test/CodeGen/X86/Float16-complex.c b/clang/test/CodeGen/X86/avx512fp16-complex.c
similarity index 96%
rename from clang/test/CodeGen/X86/Float16-complex.c
rename to clang/test/CodeGen/X86/avx512fp16-complex.c
index ebb290c976e7d..8a6b50eb0056b 100644
--- a/clang/test/CodeGen/X86/Float16-complex.c
+++ b/clang/test/CodeGen/X86/avx512fp16-complex.c
@@ -1,5 +1,4 @@
 // RUN: %clang_cc1 %s -O0 -emit-llvm -triple x86_64-unknown-unknown -target-feature +avx512fp16 -o - | FileCheck %s --check-prefix=X86
-// RUN: %clang_cc1 %s -O0 -emit-llvm -triple x86_64-unknown-unknown -o - | FileCheck %s --check-prefix=X86
 
 _Float16 _Complex add_half_rr(_Float16 a, _Float16 b) {
   // X86-LABEL: @add_half_rr(

diff  --git a/clang/test/Sema/Float16.c b/clang/test/Sema/Float16.c
index 26c604fed27aa..f0b94666f74d7 100644
--- a/clang/test/Sema/Float16.c
+++ b/clang/test/Sema/Float16.c
@@ -1,6 +1,5 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -triple i686-linux-pc %s
-// RUN: %clang_cc1 -fsyntax-only -verify -triple i686-linux-pc -target-feature +sse2 %s -DHAVE
-// RUN: %clang_cc1 -fsyntax-only -verify -triple x86_64-linux-pc %s -DHAVE
+// RUN: %clang_cc1 -fsyntax-only -verify -triple x86_64-linux-pc %s
+// RUN: %clang_cc1 -fsyntax-only -verify -triple x86_64-linux-pc -target-feature +avx512fp16 %s -DHAVE
 // RUN: %clang_cc1 -fsyntax-only -verify -triple spir-unknown-unknown %s -DHAVE
 // RUN: %clang_cc1 -fsyntax-only -verify -triple armv7a-linux-gnu %s -DHAVE
 // RUN: %clang_cc1 -fsyntax-only -verify -triple aarch64-linux-gnu %s -DHAVE

diff  --git a/clang/test/Sema/conversion-target-dep.c b/clang/test/Sema/conversion-target-dep.c
index 1b22cb8209343..958a4d8b1f076 100644
--- a/clang/test/Sema/conversion-target-dep.c
+++ b/clang/test/Sema/conversion-target-dep.c
@@ -6,7 +6,7 @@
 
 long double ld;
 double d;
-_Float16 f16;
+_Float16 f16; // x86-error {{_Float16 is not supported on this target}}
 
 int main(void) {
   ld = d; // x86-warning {{implicit conversion increases floating-point precision: 'double' to 'long double'}}

diff  --git a/clang/test/SemaCXX/Float16.cpp b/clang/test/SemaCXX/Float16.cpp
index 61b02a50687b9..f27c3839854e1 100644
--- a/clang/test/SemaCXX/Float16.cpp
+++ b/clang/test/SemaCXX/Float16.cpp
@@ -1,6 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -triple i686-linux-pc %s
-// RUN: %clang_cc1 -fsyntax-only -verify -triple i686-linux-pc -target-feature +sse2 %s -DHAVE
-// RUN: %clang_cc1 -fsyntax-only -verify -triple x86_64-linux-pc %s -DHAVE
+// RUN: %clang_cc1 -fsyntax-only -verify -triple x86_64-linux-pc %s
 // RUN: %clang_cc1 -fsyntax-only -verify -triple spir-unknown-unknown %s -DHAVE
 // RUN: %clang_cc1 -fsyntax-only -verify -triple armv7a-linux-gnu %s -DHAVE
 // RUN: %clang_cc1 -fsyntax-only -verify -triple aarch64-linux-gnu %s -DHAVE

diff  --git a/compiler-rt/test/builtins/CMakeLists.txt b/compiler-rt/test/builtins/CMakeLists.txt
index 23d9bf021cd81..d56ffc69763b6 100644
--- a/compiler-rt/test/builtins/CMakeLists.txt
+++ b/compiler-rt/test/builtins/CMakeLists.txt
@@ -44,7 +44,7 @@ foreach(arch ${BUILTIN_TEST_ARCH})
     string(REPLACE ";" " " BUILTINS_TEST_TARGET_CFLAGS "${BUILTINS_TEST_TARGET_CFLAGS}")
   endif()
 
-  if (${arch} MATCHES "arm|aarch64|arm64|i?86|x86_64|AMD64" AND COMPILER_RT_HAS_FLOAT16)
+  if (${arch} MATCHES "arm|aarch64|arm64" AND COMPILER_RT_HAS_FLOAT16)
     list(APPEND BUILTINS_TEST_TARGET_CFLAGS -DCOMPILER_RT_HAS_FLOAT16)
     string(REPLACE ";" " " BUILTINS_TEST_TARGET_CFLAGS "${BUILTINS_TEST_TARGET_CFLAGS}")
   endif()


        


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