Mesa (master): ac/llvm: add support for texturing with clamped LOD

[GitLab Mirror]

Module: Mesa
Branch: master
Commit: 0d63a1a84d409d08fd6c6f8a0c569b2620d6a600
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=0d63a1a84d409d08fd6c6f8a0c569b2620d6a600

Author: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Date:   Mon May 11 16:51:33 2020 +0200

ac/llvm: add support for texturing with clamped LOD

This is a requirement for the shaderResourceMinLod feature which
allows to clamp LOD. This uses all image_sample_*_cl variants.

All dEQP-VK.glsl.texture_functions.texture*clamp.* pass.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
Reviewed-by: Daniel Schürmann <daniel at schuermann.dev>
Reviewed-by: Marek Olšák <marek.olsak at amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4989>

---

 src/amd/llvm/ac_llvm_build.c  | 9 ++++++++-
 src/amd/llvm/ac_llvm_build.h  | 1 +
 src/amd/llvm/ac_nir_to_llvm.c | 3 +++
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/amd/llvm/ac_llvm_build.c b/src/amd/llvm/ac_llvm_build.c
index 0066a885c95..ebcb91bd4b3 100644
--- a/src/amd/llvm/ac_llvm_build.c
+++ b/src/amd/llvm/ac_llvm_build.c
@@ -2373,6 +2373,9 @@ LLVMValueRef ac_build_image_opcode(struct ac_llvm_context *ctx,
 	       (a->lod ? 1 : 0) +
 	       (a->level_zero ? 1 : 0) +
 	       (a->derivs[0] ? 1 : 0) <= 1);
+	assert((a->min_lod ? 1 : 0) +
+	       (a->lod ? 1 : 0) +
+	       (a->level_zero ? 1 : 0) <= 1);
 
 	if (a->opcode == ac_image_get_lod) {
 		switch (dim) {
@@ -2428,6 +2431,9 @@ LLVMValueRef ac_build_image_opcode(struct ac_llvm_context *ctx,
 		args[num_args++] = LLVMBuildBitCast(ctx->builder, a->coords[i], coord_type, "");
 	if (a->lod)
 		args[num_args++] = LLVMBuildBitCast(ctx->builder, a->lod, coord_type, "");
+	if (a->min_lod)
+		args[num_args++] = LLVMBuildBitCast(ctx->builder, a->min_lod, coord_type, "");
+
 	overload[num_overloads++] = sample ? ".f32" : ".i32";
 
 	args[num_args++] = a->resource;
@@ -2481,7 +2487,7 @@ LLVMValueRef ac_build_image_opcode(struct ac_llvm_context *ctx,
 	char intr_name[96];
 	snprintf(intr_name, sizeof(intr_name),
 		 "llvm.amdgcn.image.%s%s" /* base name */
-		 "%s%s%s" /* sample/gather modifiers */
+		 "%s%s%s%s" /* sample/gather modifiers */
 		 ".%s.%s%s%s%s", /* dimension and type overloads */
 		 name, atomic_subop,
 		 a->compare ? ".c" : "",
@@ -2489,6 +2495,7 @@ LLVMValueRef ac_build_image_opcode(struct ac_llvm_context *ctx,
 		 lod_suffix ? ".l" :
 		 a->derivs[0] ? ".d" :
 		 a->level_zero ? ".lz" : "",
+		 a->min_lod ? ".cl" : "",
 		 a->offset ? ".o" : "",
 		 dimname,
 		 atomic ? "i32" : "v4f32",
diff --git a/src/amd/llvm/ac_llvm_build.h b/src/amd/llvm/ac_llvm_build.h
index 2c6142e76f9..703f7ea31cc 100644
--- a/src/amd/llvm/ac_llvm_build.h
+++ b/src/amd/llvm/ac_llvm_build.h
@@ -561,6 +561,7 @@ struct ac_image_args {
 	LLVMValueRef derivs[6];
 	LLVMValueRef coords[4];
 	LLVMValueRef lod; // also used by ac_image_get_resinfo
+	LLVMValueRef min_lod;
 };
 
 LLVMValueRef ac_build_image_opcode(struct ac_llvm_context *ctx,
diff --git a/src/amd/llvm/ac_nir_to_llvm.c b/src/amd/llvm/ac_nir_to_llvm.c
index d3489614d4c..6f0d253d9c7 100644
--- a/src/amd/llvm/ac_nir_to_llvm.c
+++ b/src/amd/llvm/ac_nir_to_llvm.c
@@ -4468,6 +4468,9 @@ static void visit_tex(struct ac_nir_context *ctx, nir_tex_instr *instr)
 		case nir_tex_src_ddy:
 			ddy = get_src(ctx, instr->src[i].src);
 			break;
+		case nir_tex_src_min_lod:
+			args.min_lod = get_src(ctx, instr->src[i].src);
+			break;
 		case nir_tex_src_texture_offset:
 		case nir_tex_src_sampler_offset:
 		case nir_tex_src_plane: