radeonsi: Add buffer load functions.

v2: - Use llvm.admgcn.buffer.load instrinsics for new LLVM.
    - Code style fixes.

v3: - Code style fix.

Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>

diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 6690f053df428890a70210150f0a5d0296b0dd7f..eb573450db581ea22ebd00041dcef7cd50f27104 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -740,6 +740,120 @@ static void build_tbuffer_store_dwords(struct si_shader_context *ctx,
                            V_008F0C_BUF_NUM_FORMAT_UINT, 1, 0, 1, 1, 0);
 }
 
+static LLVMValueRef build_buffer_load(struct si_shader_context *ctx,
+                                      LLVMValueRef rsrc,
+                                      int num_channels,
+                                      LLVMValueRef vindex,
+                                      LLVMValueRef voffset,
+                                      LLVMValueRef soffset,
+                                      unsigned inst_offset,
+                                      unsigned glc,
+                                      unsigned slc)
+{
+       struct gallivm_state *gallivm = &ctx->radeon_bld.gallivm;
+       unsigned func = CLAMP(num_channels, 1, 3) - 1;
+
+       if (HAVE_LLVM >= 0x309) {
+               LLVMValueRef args[] = {
+                       LLVMBuildBitCast(gallivm->builder, rsrc, ctx->v4i32, ""),
+                       vindex ? vindex : LLVMConstInt(ctx->i32, 0, 0),
+                       LLVMConstInt(ctx->i32, inst_offset, 0),
+                       LLVMConstInt(ctx->i1, glc, 0),
+                       LLVMConstInt(ctx->i1, slc, 0)
+               };
+
+               LLVMTypeRef types[] = {ctx->f32, LLVMVectorType(ctx->f32, 2),
+                                      ctx->v4f32};
+               const char *type_names[] = {"f32", "v2f32", "v4f32"};
+               char name[256];
+
+               if (voffset) {
+                       args[2] = LLVMBuildAdd(gallivm->builder, args[2], voffset,
+                                              "");
+               }
+
+               if (soffset) {
+                       args[2] = LLVMBuildAdd(gallivm->builder, args[2], soffset,
+                                              "");
+               }
+
+               snprintf(name, sizeof(name), "llvm.amdgcn.buffer.load.%s",
+                        type_names[func]);
+
+               return lp_build_intrinsic(gallivm->builder, name, types[func], args,
+                                         ARRAY_SIZE(args), LLVMReadOnlyAttribute |
+                                         LLVMNoUnwindAttribute);
+       } else {
+               LLVMValueRef args[] = {
+                       LLVMBuildBitCast(gallivm->builder, rsrc, ctx->v16i8, ""),
+                       voffset ? voffset : vindex,
+                       soffset,
+                       LLVMConstInt(ctx->i32, inst_offset, 0),
+                       LLVMConstInt(ctx->i32, voffset ? 1 : 0, 0), // offen
+                       LLVMConstInt(ctx->i32, vindex ? 1 : 0, 0), //idxen
+                       LLVMConstInt(ctx->i32, glc, 0),
+                       LLVMConstInt(ctx->i32, slc, 0),
+                       LLVMConstInt(ctx->i32, 0, 0), // TFE
+               };
+
+               LLVMTypeRef types[] = {ctx->i32, LLVMVectorType(ctx->i32, 2),
+                                      ctx->v4i32};
+               const char *type_names[] = {"i32", "v2i32", "v4i32"};
+               const char *arg_type = "i32";
+               char name[256];
+
+               if (voffset && vindex) {
+                       LLVMValueRef vaddr[] = {vindex, voffset};
+
+                       arg_type = "v2i32";
+                       args[1] = lp_build_gather_values(gallivm, vaddr, 2);
+               }
+
+               snprintf(name, sizeof(name), "llvm.SI.buffer.load.dword.%s.%s",
+                        type_names[func], arg_type);
+
+               return lp_build_intrinsic(gallivm->builder, name, types[func], args,
+                                         ARRAY_SIZE(args), LLVMReadOnlyAttribute |
+                                         LLVMNoUnwindAttribute);
+       }
+}
+
+static LLVMValueRef buffer_load(struct lp_build_tgsi_context *bld_base,
+                                enum tgsi_opcode_type type, unsigned swizzle,
+                                LLVMValueRef buffer, LLVMValueRef offset,
+                                LLVMValueRef base)
+{
+       struct si_shader_context *ctx = si_shader_context(bld_base);
+       struct gallivm_state *gallivm = bld_base->base.gallivm;
+       LLVMValueRef value, value2;
+       LLVMTypeRef llvm_type = tgsi2llvmtype(bld_base, type);
+       LLVMTypeRef vec_type = LLVMVectorType(llvm_type, 4);
+
+       if (swizzle == ~0) {
+               value = build_buffer_load(ctx, buffer, 4, NULL, base, offset,
+                                         0, 1, 0);
+
+               return LLVMBuildBitCast(gallivm->builder, value, vec_type, "");
+       }
+
+       if (type != TGSI_TYPE_DOUBLE) {
+               value = build_buffer_load(ctx, buffer, 4, NULL, base, offset,
+                                         0, 1, 0);
+
+               value = LLVMBuildBitCast(gallivm->builder, value, vec_type, "");
+               return LLVMBuildExtractElement(gallivm->builder, value,
+                                   lp_build_const_int32(gallivm, swizzle), "");
+       }
+
+       value = build_buffer_load(ctx, buffer, 1, NULL, base, offset,
+                                 swizzle * 4, 1, 0);
+
+       value2 = build_buffer_load(ctx, buffer, 1, NULL, base, offset,
+                                  swizzle * 4 + 4, 1, 0);
+
+       return radeon_llvm_emit_fetch_double(bld_base, value, value2);
+}
+
 /**
  * Load from LDS.
  *