gallivm: add no-signed-zeros-fp-math option to lp_create_builder (v2)

v2: define lp_float_mode

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

src/gallium/auxiliary/gallivm/lp_bld_misc.cpp

@@ -781,15 +781,24 @@ lp_is_function(LLVMValueRef v)
 }
 
 extern "C" LLVMBuilderRef
-lp_create_builder(LLVMContextRef ctx, bool unsafe_fpmath)
+lp_create_builder(LLVMContextRef ctx, enum lp_float_mode float_mode)
 {
    LLVMBuilderRef builder = LLVMCreateBuilderInContext(ctx);
 
 #if HAVE_LLVM >= 0x0308
-   if (unsafe_fpmath) {
-      llvm::FastMathFlags flags;
+   llvm::FastMathFlags flags;
+
+   switch (float_mode) {
+   case LP_FLOAT_MODE_DEFAULT:
+      break;
+   case LP_FLOAT_MODE_NO_SIGNED_ZEROS_FP_MATH:
+      flags.setNoSignedZeros();
+      llvm::unwrap(builder)->setFastMathFlags(flags);
+      break;
+   case LP_FLOAT_MODE_UNSAFE_FP_MATH:
       flags.setUnsafeAlgebra();
       llvm::unwrap(builder)->setFastMathFlags(flags);
+      break;
    }
 #endif
 

src/gallium/auxiliary/gallivm/lp_bld_misc.h

@@ -82,8 +82,14 @@ lp_get_called_value(LLVMValueRef call);
 extern bool
 lp_is_function(LLVMValueRef v);
 
+enum lp_float_mode {
+   LP_FLOAT_MODE_DEFAULT,
+   LP_FLOAT_MODE_NO_SIGNED_ZEROS_FP_MATH,
+   LP_FLOAT_MODE_UNSAFE_FP_MATH,
+};
+
 extern LLVMBuilderRef
-lp_create_builder(LLVMContextRef ctx, bool unsafe_fpmath);
+lp_create_builder(LLVMContextRef ctx, enum lp_float_mode float_mode);
 
 #ifdef __cplusplus
 }

src/gallium/drivers/radeonsi/si_shader_tgsi_setup.c

@@ -1267,8 +1267,12 @@ void si_llvm_context_init(struct si_shader_context *ctx,
 #endif
 
 	bool unsafe_fpmath = (sscreen->b.debug_flags & DBG_UNSAFE_MATH) != 0;
+	enum lp_float_mode float_mode =
+		unsafe_fpmath ? LP_FLOAT_MODE_UNSAFE_FP_MATH :
+				LP_FLOAT_MODE_DEFAULT;
+
 	ctx->gallivm.builder = lp_create_builder(ctx->gallivm.context,
-						 unsafe_fpmath);
+						 float_mode);
 
 	ac_llvm_context_init(&ctx->ac, ctx->gallivm.context);
 	ctx->ac.module = ctx->gallivm.module;