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 1b17dd4613f25eddf1d966c01f09c1733d7ba8dd..171ccaadd5c6599d497f40ce6c38ff691207043f 100644 (file)
--- 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() {