radeonsi: communicate cube map coordinates more explicitly

v2: fix compile error that snuck in during rebase

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

diff --git a/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c b/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c
index 0a49bc2..1c37345 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c
+++ b/src/gallium/drivers/radeonsi/si_shader_tgsi_alu.c
@@ -907,23 +907,33 @@ void si_shader_context_init_alu(struct lp_build_tgsi_context *bld_base)
        bld_base->op_actions[TGSI_OPCODE_I64DIV].emit = emit_idiv;
 }
 
-static LLVMValueRef build_cube_intrinsic(struct gallivm_state *gallivm,
-                                        LLVMValueRef in[3])
+/* Coordinates for cube map selection. sc, tc, and ma are as in Table 8.27
+ * of the OpenGL 4.5 (Compatibility Profile) specification, except ma is
+ * already multiplied by two. id is the cube face number.
+ */
+struct cube_selection_coords {
+       LLVMValueRef stc[2];
+       LLVMValueRef ma;
+       LLVMValueRef id;
+};
+
+static void build_cube_intrinsic(struct gallivm_state *gallivm,
+                                LLVMValueRef in[3],
+                                struct cube_selection_coords *out)
 {
+       LLVMBuilderRef builder = gallivm->builder;
+
        if (HAVE_LLVM >= 0x0309) {
                LLVMTypeRef f32 = LLVMTypeOf(in[0]);
-               LLVMValueRef out[4];
 
-               out[0] = lp_build_intrinsic(gallivm->builder, "llvm.amdgcn.cubetc",
+               out->stc[1] = lp_build_intrinsic(builder, "llvm.amdgcn.cubetc",
                                            f32, in, 3, LP_FUNC_ATTR_READNONE);
-               out[1] = lp_build_intrinsic(gallivm->builder, "llvm.amdgcn.cubesc",
+               out->stc[0] = lp_build_intrinsic(builder, "llvm.amdgcn.cubesc",
                                            f32, in, 3, LP_FUNC_ATTR_READNONE);
-               out[2] = lp_build_intrinsic(gallivm->builder, "llvm.amdgcn.cubema",
+               out->ma = lp_build_intrinsic(builder, "llvm.amdgcn.cubema",
                                            f32, in, 3, LP_FUNC_ATTR_READNONE);
-               out[3] = lp_build_intrinsic(gallivm->builder, "llvm.amdgcn.cubeid",
+               out->id = lp_build_intrinsic(builder, "llvm.amdgcn.cubeid",
                                            f32, in, 3, LP_FUNC_ATTR_READNONE);
-
-               return lp_build_gather_values(gallivm, out, 4);
        } else {
                LLVMValueRef c[4] = {
                        in[0],
@@ -933,9 +943,19 @@ static LLVMValueRef build_cube_intrinsic(struct gallivm_state *gallivm,
                };
                LLVMValueRef vec = lp_build_gather_values(gallivm, c, 4);
 
-               return lp_build_intrinsic(gallivm->builder, "llvm.AMDGPU.cube",
+               LLVMValueRef tmp =
+                       lp_build_intrinsic(builder, "llvm.AMDGPU.cube",
                                          LLVMTypeOf(vec), &vec, 1,
                                          LP_FUNC_ATTR_READNONE);
+
+               out->stc[1] = LLVMBuildExtractElement(builder, tmp,
+                               lp_build_const_int32(gallivm, 0), "");
+               out->stc[0] = LLVMBuildExtractElement(builder, tmp,
+                               lp_build_const_int32(gallivm, 1), "");
+               out->ma = LLVMBuildExtractElement(builder, tmp,
+                               lp_build_const_int32(gallivm, 2), "");
+               out->id = LLVMBuildExtractElement(builder, tmp,
+                               lp_build_const_int32(gallivm, 3), "");
        }
 }
 
@@ -945,36 +965,26 @@ static void si_llvm_cube_to_2d_coords(struct lp_build_tgsi_context *bld_base,
        struct gallivm_state *gallivm = bld_base->base.gallivm;
        LLVMBuilderRef builder = gallivm->builder;
        LLVMTypeRef type = bld_base->base.elem_type;
-       LLVMValueRef coords[4];
+       struct cube_selection_coords coords;
+       LLVMValueRef invma;
        LLVMValueRef mad_args[3];
-       LLVMValueRef v;
-       unsigned i;
-
-       v = build_cube_intrinsic(gallivm, in);
 
-       for (i = 0; i < 4; ++i)
-               coords[i] = LLVMBuildExtractElement(builder, v,
-                                                   lp_build_const_int32(gallivm, i), "");
+       build_cube_intrinsic(gallivm, in, &coords);
 
-       coords[2] = lp_build_intrinsic(builder, "llvm.fabs.f32",
-                       type, &coords[2], 1, LP_FUNC_ATTR_READNONE);
-       coords[2] = lp_build_emit_llvm_unary(bld_base, TGSI_OPCODE_RCP, coords[2]);
+       invma = lp_build_intrinsic(builder, "llvm.fabs.f32",
+                       type, &coords.ma, 1, LP_FUNC_ATTR_READNONE);
+       invma = lp_build_emit_llvm_unary(bld_base, TGSI_OPCODE_RCP, invma);
 
-       mad_args[1] = coords[2];
+       mad_args[1] = invma;
        mad_args[2] = LLVMConstReal(type, 1.5);
 
-       mad_args[0] = coords[0];
-       coords[0] = lp_build_emit_llvm_ternary(bld_base, TGSI_OPCODE_MAD,
-                       mad_args[0], mad_args[1], mad_args[2]);
-
-       mad_args[0] = coords[1];
-       coords[1] = lp_build_emit_llvm_ternary(bld_base, TGSI_OPCODE_MAD,
-                       mad_args[0], mad_args[1], mad_args[2]);
+       for (int i = 0; i < 2; ++i) {
+               mad_args[0] = coords.stc[i];
+               out[i] = lp_build_emit_llvm_ternary(bld_base, TGSI_OPCODE_MAD,
+                               mad_args[0], mad_args[1], mad_args[2]);
+       }
 
-       /* apply xyz = yxw swizzle to cooords */
-       out[0] = coords[1];
-       out[1] = coords[0];
-       out[2] = coords[3];
+       out[2] = coords.id;
 }
 
 void si_prepare_cube_coords(struct lp_build_tgsi_context *bld_base,