From: Grigori Goronzy <greg@chown.ath.cx>
Date: Thu, 17 Jul 2014 16:44:25 +0000 (+0200)
Subject: radeon/llvm: enable unsafe math for graphics shaders
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=0e9cdedd2e3943bdb7f3543a3508b883b167e427;p=mesa.git

radeon/llvm: enable unsafe math for graphics shaders

Accuracy of some operations was recently improved in the R600 backend,
at the cost of slower code. This is required for compute shaders,
but not for graphics shaders. Add unsafe-fp-math hint to make LLVM
generate faster but possibly less accurate code.

Piglit didn't indicate any regressions.

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>
---

diff --git a/src/gallium/drivers/radeon/radeon_llvm_emit.c b/src/gallium/drivers/radeon/radeon_llvm_emit.c
index 1b17dd4613f..171ccaadd5c 100644
--- a/src/gallium/drivers/radeon/radeon_llvm_emit.c
+++ b/src/gallium/drivers/radeon/radeon_llvm_emit.c
@@ -26,6 +26,7 @@
 #include "radeon_llvm_emit.h"
 #include "radeon_elf_util.h"
 #include "util/u_memory.h"
+#include "pipe/p_shader_tokens.h"
 
 #include <llvm-c/Target.h>
 #include <llvm-c/TargetMachine.h>
@@ -50,6 +51,10 @@ void radeon_llvm_shader_type(LLVMValueRef F, unsigned type)
   sprintf(Str, "%1d", type);
 
   LLVMAddTargetDependentFunctionAttr(F, "ShaderType", Str);
+
+  if (type != TGSI_PROCESSOR_COMPUTE) {
+    LLVMAddTargetDependentFunctionAttr(F, "unsafe-fp-math", "true");
+  }
 }
 
 static void init_r600_target() {