r249733 - Handle sse turning on mmx, but no -mmx not turning off SSE.

Eric Christopher via cfe-commits cfe-commits at lists.llvm.org
Thu Oct 8 13:10:18 PDT 2015


Author: echristo
Date: Thu Oct  8 15:10:18 2015
New Revision: 249733

URL: http://llvm.org/viewvc/llvm-project?rev=249733&view=rev
Log:
Handle sse turning on mmx, but no -mmx not turning off SSE.

Rationale :

// sse3
__m128d test_mm_addsub_pd(__m128d A, __m128d B) {
  return _mm_addsub_pd(A, B);
}

// mmx
void shift(__m64 a, __m64 b, int c) {
  _mm_slli_pi16(a, c);
  _mm_slli_pi32(a, c);
  _mm_slli_si64(a, c);
  _mm_srli_pi16(a, c);
  _mm_srli_pi32(a, c);
  _mm_srli_si64(a, c);
  _mm_srai_pi16(a, c);
  _mm_srai_pi32(a, c);
}

clang -msse3 -mno-mmx file.c -c

For this code we should be able to explicitly turn off MMX
without affecting the compilation of the SSE3 function and then
diagnose and error on compiling the MMX function.

This is a preparatory patch to the actual diagnosis code which is
coming in a future patch. This sets us up to have the correct information
where we need it and verifies that it's being emitted for the backend
to handle.

Added:
    cfe/trunk/test/CodeGen/attr-target-x86-mmx.c
Modified:
    cfe/trunk/lib/Basic/Targets.cpp
    cfe/trunk/test/CodeGen/attr-target-x86.c

Modified: cfe/trunk/lib/Basic/Targets.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Basic/Targets.cpp?rev=249733&r1=249732&r2=249733&view=diff
==============================================================================
--- cfe/trunk/lib/Basic/Targets.cpp (original)
+++ cfe/trunk/lib/Basic/Targets.cpp Thu Oct  8 15:10:18 2015
@@ -2725,6 +2725,14 @@ bool X86TargetInfo::initFeatureMap(
           FeaturesVec.end())
     Features["prfchw"] = true;
 
+  // Additionally, if SSE is enabled and mmx is not explicitly disabled,
+  // then enable MMX.
+  I = Features.find("sse");
+  if (I != Features.end() && I->getValue() == true &&
+      std::find(FeaturesVec.begin(), FeaturesVec.end(), "-mmx") ==
+          FeaturesVec.end())
+    Features["mmx"] = true;
+
   return true;
 }
 
@@ -3004,17 +3012,6 @@ bool X86TargetInfo::handleTargetFeatures
     return false;
   }
 
-  // Don't tell the backend if we're turning off mmx; it will end up disabling
-  // SSE, which we don't want.
-  // Additionally, if SSE is enabled and mmx is not explicitly disabled,
-  // then enable MMX.
-  std::vector<std::string>::iterator it;
-  it = std::find(Features.begin(), Features.end(), "-mmx");
-  if (it != Features.end())
-    Features.erase(it);
-  else if (SSELevel > NoSSE)
-    MMX3DNowLevel = std::max(MMX3DNowLevel, MMX);
-
   SimdDefaultAlign =
       hasFeature("avx512f") ? 512 : hasFeature("avx") ? 256 : 128;
   return true;

Added: cfe/trunk/test/CodeGen/attr-target-x86-mmx.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/attr-target-x86-mmx.c?rev=249733&view=auto
==============================================================================
--- cfe/trunk/test/CodeGen/attr-target-x86-mmx.c (added)
+++ cfe/trunk/test/CodeGen/attr-target-x86-mmx.c Thu Oct  8 15:10:18 2015
@@ -0,0 +1,22 @@
+// RUN: %clang_cc1 -triple i386-linux-gnu -emit-llvm %s -o - | FileCheck %s
+// Picking a cpu that doesn't have mmx or sse by default so we can enable it later.
+
+#define __MM_MALLOC_H
+
+#include <x86intrin.h>
+
+// Verify that when we turn on sse that we also turn on mmx.
+void __attribute__((target("sse"))) shift(__m64 a, __m64 b, int c) {
+  _mm_slli_pi16(a, c);
+  _mm_slli_pi32(a, c);
+  _mm_slli_si64(a, c);
+
+  _mm_srli_pi16(a, c);
+  _mm_srli_pi32(a, c);
+  _mm_srli_si64(a, c);
+
+  _mm_srai_pi16(a, c);
+  _mm_srai_pi32(a, c);
+}
+
+// CHECK: "target-features"="+mmx,+sse"

Modified: cfe/trunk/test/CodeGen/attr-target-x86.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/attr-target-x86.c?rev=249733&r1=249732&r2=249733&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/attr-target-x86.c (original)
+++ cfe/trunk/test/CodeGen/attr-target-x86.c Thu Oct  8 15:10:18 2015
@@ -16,6 +16,8 @@ int bar(int a) { return baz(a) + foo(a);
 int __attribute__((target("avx,      sse4.2,      arch=   ivybridge"))) qux(int a) { return 4; }
 int __attribute__((target("no-aes, arch=ivybridge"))) qax(int a) { return 4; }
 
+int __attribute__((target("no-mmx"))) qq(int a) { return 40; }
+
 // Check that we emit the additional subtarget and cpu features for foo and not for baz or bar.
 // CHECK: baz{{.*}} #0
 // CHECK: foo{{.*}} #1
@@ -28,8 +30,10 @@ int __attribute__((target("no-aes, arch=
 // CHECK: bar{{.*}} #0
 // CHECK: qux{{.*}} #1
 // CHECK: qax{{.*}} #4
-// CHECK: #0 = {{.*}}"target-cpu"="x86-64" "target-features"="+sse,+sse2"
-// CHECK: #1 = {{.*}}"target-cpu"="ivybridge" "target-features"="+aes,+avx,+cx16,+f16c,+fsgsbase,+pclmul,+popcnt,+rdrnd,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3"
-// CHECK: #2 = {{.*}}"target-cpu"="x86-64" "target-features"="+sse,-aes,-avx,-avx2,-avx512bw,-avx512cd,-avx512dq,-avx512er,-avx512f,-avx512pf,-avx512vl,-f16c,-fma,-fma4,-pclmul,-sha,-sse2,-sse3,-sse4.1,-sse4.2,-sse4a,-ssse3,-xop"
-// CHECK: #3 = {{.*}}"target-cpu"="x86-64" "target-features"="+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3"
-// CHECK: #4 = {{.*}}"target-cpu"="ivybridge" "target-features"="+avx,+cx16,+f16c,+fsgsbase,+pclmul,+popcnt,+rdrnd,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,-aes"
+// CHECK: qq{{.*}} #5
+// CHECK: #0 = {{.*}}"target-cpu"="x86-64" "target-features"="+mmx,+sse,+sse2"
+// CHECK: #1 = {{.*}}"target-cpu"="ivybridge" "target-features"="+aes,+avx,+cx16,+f16c,+fsgsbase,+mmx,+pclmul,+popcnt,+rdrnd,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3"
+// CHECK: #2 = {{.*}}"target-cpu"="x86-64" "target-features"="+mmx,+sse,-aes,-avx,-avx2,-avx512bw,-avx512cd,-avx512dq,-avx512er,-avx512f,-avx512pf,-avx512vl,-f16c,-fma,-fma4,-pclmul,-sha,-sse2,-sse3,-sse4.1,-sse4.2,-sse4a,-ssse3,-xop"
+// CHECK: #3 = {{.*}}"target-cpu"="x86-64" "target-features"="+mmx,+popcnt,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3"
+// CHECK: #4 = {{.*}}"target-cpu"="ivybridge" "target-features"="+avx,+cx16,+f16c,+fsgsbase,+mmx,+pclmul,+popcnt,+rdrnd,+sse,+sse2,+sse3,+sse4.1,+sse4.2,+ssse3,-aes"
+// CHECK: #5 = {{.*}}"target-cpu"="x86-64" "target-features"="+sse,+sse2,-3dnow,-3dnowa,-mmx"




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