[Mesa-dev] [PATCH] gallivm: Explicitly disable unsupported CPU features.

[Jose Fonseca]

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92214
---
 src/gallium/auxiliary/gallivm/lp_bld_misc.cpp | 69 ++++++++++++---------------
 1 file changed, 31 insertions(+), 38 deletions(-)

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
index e70a75f..0781e36 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
+++ b/src/gallium/auxiliary/gallivm/lp_bld_misc.cpp
@@ -498,50 +498,43 @@ lp_build_create_jit_compiler_for_module(LLVMExecutionEngineRef *OutJIT,
    }
 
    llvm::SmallVector<std::string, 16> MAttrs;
-   if (util_cpu_caps.has_sse) {
-      MAttrs.push_back("+sse");
-   }
-   if (util_cpu_caps.has_sse2) {
-      MAttrs.push_back("+sse2");
-   }
-   if (util_cpu_caps.has_sse3) {
-      MAttrs.push_back("+sse3");
-   }
-   if (util_cpu_caps.has_ssse3) {
-      MAttrs.push_back("+ssse3");
-   }
-   if (util_cpu_caps.has_sse4_1) {
+
+#if defined(PIPE_ARCH_X86) || defined(PIPE_ARCH_X86_64)
+   /*
+    * We need to unset attributes because sometimes LLVM mistakenly assumes
+    * certain features are present given the processor name.
+    *
+    * https://bugs.freedesktop.org/show_bug.cgi?id=92214
+    */
+   MAttrs.push_back(util_cpu_caps.has_sse    ? "+sse"    : "-sse"   );
+   MAttrs.push_back(util_cpu_caps.has_sse2   ? "+sse2"   : "-sse2"  );
+   MAttrs.push_back(util_cpu_caps.has_sse3   ? "+sse3"   : "-sse3"  );
+   MAttrs.push_back(util_cpu_caps.has_ssse3  ? "+ssse3"  : "-ssse3" );
 #if HAVE_LLVM >= 0x0304
-      MAttrs.push_back("+sse4.1");
+   MAttrs.push_back(util_cpu_caps.has_sse4_1 ? "+sse4.1" : "-sse4.1");
 #else
-      MAttrs.push_back("+sse41");
+   MAttrs.push_back(util_cpu_caps.has_sse4_1 ? "+sse41"  : "-sse41" );
 #endif
-   }
-   if (util_cpu_caps.has_sse4_2) {
 #if HAVE_LLVM >= 0x0304
-      MAttrs.push_back("+sse4.2");
+   MAttrs.push_back(util_cpu_caps.has_sse4_2 ? "+sse4.2" : "-sse4.2");
 #else
-      MAttrs.push_back("+sse42");
+   MAttrs.push_back(util_cpu_caps.has_sse4_2 ? "+sse42"  : "-sse42" );
 #endif
-   }
-   if (util_cpu_caps.has_avx) {
-      /*
-       * AVX feature is not automatically detected from CPUID by the X86 target
-       * yet, because the old (yet default) JIT engine is not capable of
-       * emitting the opcodes. On newer llvm versions it is and at least some
-       * versions (tested with 3.3) will emit avx opcodes without this anyway.
-       */
-      MAttrs.push_back("+avx");
-      if (util_cpu_caps.has_f16c) {
-         MAttrs.push_back("+f16c");
-      }
-      if (util_cpu_caps.has_avx2) {
-         MAttrs.push_back("+avx2");
-      }
-   }
-   if (util_cpu_caps.has_altivec) {
-      MAttrs.push_back("+altivec");
-   }
+   /*
+    * AVX feature is not automatically detected from CPUID by the X86 target
+    * yet, because the old (yet default) JIT engine is not capable of
+    * emitting the opcodes. On newer llvm versions it is and at least some
+    * versions (tested with 3.3) will emit avx opcodes without this anyway.
+    */
+   MAttrs.push_back(util_cpu_caps.has_avx  ? "+avx"  : "-avx");
+   MAttrs.push_back(util_cpu_caps.has_f16c ? "+f16c" : "-f16c");
+   MAttrs.push_back(util_cpu_caps.has_avx2 ? "+avx2" : "-avx2");
+#endif
+
+#if defined(PIPE_ARCH_PPC)
+   MAttrs.push_back(util_cpu_caps.has_altivec ? "+altivec" : "-altivec");
+#endif
+
    builder.setMAttrs(MAttrs);
 
 #if HAVE_LLVM >= 0x0305
-- 
2.1.4