radv: Use different intrinsic for ubo loads.
authorBas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Mon, 28 Nov 2016 23:18:43 +0000 (00:18 +0100)
committerBas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Tue, 29 Nov 2016 07:36:16 +0000 (08:36 +0100)
Not sure about the deprecation path, but this intrinsic
can be lowered to SMEM loads. This results in a significant
Talos performance improvement.

v2: Fix for LLVM attribute changes.

Signed-off-by: Bas Nieuwenhuizen <basni@google.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
src/amd/common/ac_nir_to_llvm.c

index f623cc0..c9b0106 100644 (file)
@@ -2035,6 +2035,34 @@ static LLVMValueRef visit_load_buffer(struct nir_to_llvm_context *ctx,
                                get_def_type(ctx, &instr->dest.ssa), "");
 }
 
+static LLVMValueRef visit_load_ubo_buffer(struct nir_to_llvm_context *ctx,
+                                          nir_intrinsic_instr *instr)
+{
+       const nir_intrinsic_info *info = &nir_intrinsic_infos[instr->intrinsic];
+       const char *load_name;
+       LLVMTypeRef data_type = ctx->f32;
+       LLVMValueRef results[4], ret;
+       LLVMValueRef rsrc = get_src(ctx, instr->src[0]);
+       LLVMValueRef offset = get_src(ctx, instr->src[1]);
+
+       rsrc = LLVMBuildBitCast(ctx->builder, rsrc, LLVMVectorType(ctx->i8, 16), "");
+
+       for (unsigned i = 0; i < instr->num_components; ++i) {
+               LLVMValueRef params[] = {
+                       rsrc,
+                       LLVMBuildAdd(ctx->builder, LLVMConstInt(ctx->i32, 4 * i, 0),
+                                    offset, "")
+               };
+               results[i] = emit_llvm_intrinsic(ctx, "llvm.SI.load.const", ctx->f32,
+                                                params, 2, AC_FUNC_ATTR_READNONE);
+       }
+
+
+       ret = build_gather_values(ctx, results, instr->num_components);
+       return LLVMBuildBitCast(ctx->builder, ret,
+                               get_def_type(ctx, &instr->dest.ssa), "");
+}
+
 static void
 radv_get_deref_offset(struct nir_to_llvm_context *ctx, nir_deref *tail,
                       bool vs_in, unsigned *const_out, LLVMValueRef *indir_out)
@@ -2956,7 +2984,7 @@ static void visit_intrinsic(struct nir_to_llvm_context *ctx,
                result = visit_atomic_ssbo(ctx, instr);
                break;
        case nir_intrinsic_load_ubo:
-               result = visit_load_buffer(ctx, instr);
+               result = visit_load_ubo_buffer(ctx, instr);
                break;
        case nir_intrinsic_get_buffer_size:
                result = visit_get_buffer_size(ctx, instr);