radeonsi: simplify si_llvm_emit_ddxy

si_llvm_emit_ddxy is called once per element, so we don't have to generate
code for 4 elements at once.

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>

diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 414810e..c150ae4 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -5005,19 +5005,14 @@ static void si_llvm_emit_ddxy(
 {
        struct si_shader_context *ctx = si_shader_context(bld_base);
        struct gallivm_state *gallivm = bld_base->base.gallivm;
-       const struct tgsi_full_instruction *inst = emit_data->inst;
-       unsigned opcode = inst->Instruction.Opcode;
-       LLVMValueRef store_ptr, load_ptr0, load_ptr1, thread_id;
-       LLVMValueRef tl, trbl, result[4];
-       LLVMValueRef tl_tid, trbl_tid;
-       unsigned swizzle[4];
-       unsigned c;
+       unsigned opcode = emit_data->info->opcode;
+       LLVMValueRef thread_id, tl, trbl, tl_tid, trbl_tid, val, args[2];
        int idx;
        unsigned mask;
        bool has_ds_bpermute = HAVE_LLVM >= 0x0309 &&
                               ctx->screen->b.chip_class >= VI;
 
-       thread_id = get_thread_id(ctx);;
+       thread_id = get_thread_id(ctx);
 
        if (opcode == TGSI_OPCODE_DDX_FINE)
                mask = TID_MASK_LEFT;
@@ -5034,55 +5029,38 @@ static void si_llvm_emit_ddxy(
        trbl_tid = LLVMBuildAdd(gallivm->builder, tl_tid,
                                  lp_build_const_int32(gallivm, idx), "");
 
-       if (!has_ds_bpermute) {
-               store_ptr = build_gep0(ctx, ctx->lds, thread_id);
-               load_ptr0 = build_gep0(ctx, ctx->lds, tl_tid);
-               load_ptr1 = build_gep0(ctx, ctx->lds, trbl_tid);
-       }
-
-       for (c = 0; c < 4; ++c) {
-               unsigned i;
-               LLVMValueRef val;
-               LLVMValueRef args[2];
-
-               swizzle[c] = tgsi_util_get_full_src_register_swizzle(&inst->Src[0], c);
-               for (i = 0; i < c; ++i) {
-                       if (swizzle[i] == swizzle[c]) {
-                               result[c] = result[i];
-                               break;
-                       }
-               }
-               if (i != c)
-                       continue;
-
-               val = LLVMBuildBitCast(gallivm->builder,
-                               lp_build_emit_fetch(bld_base, inst, 0, c),
-                                               ctx->i32, "");
+       val = LLVMBuildBitCast(gallivm->builder, emit_data->args[0], ctx->i32, "");
 
-               if (has_ds_bpermute) {
-                       args[0] = LLVMBuildMul(gallivm->builder, tl_tid,
-                                        lp_build_const_int32(gallivm, 4), "");
-                       args[1] = val;
-                       tl = lp_build_intrinsic(gallivm->builder,
+       if (has_ds_bpermute) {
+               args[0] = LLVMBuildMul(gallivm->builder, tl_tid,
+                                      lp_build_const_int32(gallivm, 4), "");
+               args[1] = val;
+               tl = lp_build_intrinsic(gallivm->builder,
                                        "llvm.amdgcn.ds.bpermute", ctx->i32,
                                        args, 2, LLVMReadNoneAttribute);
 
-                       args[0] = LLVMBuildMul(gallivm->builder, trbl_tid,
-                                        lp_build_const_int32(gallivm, 4), "");
-                       trbl = lp_build_intrinsic(gallivm->builder,
-                                       "llvm.amdgcn.ds.bpermute", ctx->i32,
-                                       args, 2, LLVMReadNoneAttribute);
-               } else {
-                       LLVMBuildStore(gallivm->builder, val, store_ptr);
-                       tl = LLVMBuildLoad(gallivm->builder, load_ptr0, "");
-                       trbl = LLVMBuildLoad(gallivm->builder, load_ptr1, "");
-               }
-               tl = LLVMBuildBitCast(gallivm->builder, tl, ctx->f32, "");
-               trbl = LLVMBuildBitCast(gallivm->builder, trbl, ctx->f32, "");
-               result[c] = LLVMBuildFSub(gallivm->builder, trbl, tl, "");
+               args[0] = LLVMBuildMul(gallivm->builder, trbl_tid,
+                                      lp_build_const_int32(gallivm, 4), "");
+               trbl = lp_build_intrinsic(gallivm->builder,
+                                         "llvm.amdgcn.ds.bpermute", ctx->i32,
+                                         args, 2, LLVMReadNoneAttribute);
+       } else {
+               LLVMValueRef store_ptr, load_ptr0, load_ptr1;
+
+               store_ptr = build_gep0(ctx, ctx->lds, thread_id);
+               load_ptr0 = build_gep0(ctx, ctx->lds, tl_tid);
+               load_ptr1 = build_gep0(ctx, ctx->lds, trbl_tid);
+
+               LLVMBuildStore(gallivm->builder, val, store_ptr);
+               tl = LLVMBuildLoad(gallivm->builder, load_ptr0, "");
+               trbl = LLVMBuildLoad(gallivm->builder, load_ptr1, "");
        }
 
-       emit_data->output[0] = lp_build_gather_values(gallivm, result, 4);
+       tl = LLVMBuildBitCast(gallivm->builder, tl, ctx->f32, "");
+       trbl = LLVMBuildBitCast(gallivm->builder, trbl, ctx->f32, "");
+
+       emit_data->output[emit_data->chan] =
+               LLVMBuildFSub(gallivm->builder, trbl, tl, "");
 }
 
 /*