radeonsi: Implement alpha testing in pixel shader.
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
diff --git a/src/gallium/drivers/radeonsi/radeonsi_shader.c b/src/gallium/drivers/radeonsi/radeonsi_shader.c
index ce2095c..ec9d9f3 100644
--- a/src/gallium/drivers/radeonsi/radeonsi_shader.c
+++ b/src/gallium/drivers/radeonsi/radeonsi_shader.c
@@ -31,6 +31,7 @@
#include "gallivm/lp_bld_const.h"
#include "gallivm/lp_bld_gather.h"
#include "gallivm/lp_bld_intr.h"
+#include "gallivm/lp_bld_logic.h"
#include "gallivm/lp_bld_tgsi.h"
#include "radeon_llvm.h"
#include "radeon_llvm_emit.h"
@@ -546,6 +547,37 @@
}
+static void si_alpha_test(struct lp_build_tgsi_context *bld_base,
+ unsigned index)
+{
+ struct si_shader_context *si_shader_ctx = si_shader_context(bld_base);
+ struct gallivm_state *gallivm = bld_base->base.gallivm;
+
+ if (si_shader_ctx->key.alpha_func != PIPE_FUNC_NEVER) {
+ LLVMValueRef out_ptr = si_shader_ctx->radeon_bld.soa.outputs[index][3];
+ LLVMValueRef alpha_pass =
+ lp_build_cmp(&bld_base->base,
+ si_shader_ctx->key.alpha_func,
+ LLVMBuildLoad(gallivm->builder, out_ptr, ""),
+ lp_build_const_float(gallivm, si_shader_ctx->key.alpha_ref));
+ LLVMValueRef arg =
+ lp_build_select(&bld_base->base,
+ alpha_pass,
+ lp_build_const_float(gallivm, 1.0f),
+ lp_build_const_float(gallivm, -1.0f));
+
+ build_intrinsic(gallivm->builder,
+ "llvm.AMDGPU.kill",
+ LLVMVoidTypeInContext(gallivm->context),
+ &arg, 1, 0);
+ } else {
+ build_intrinsic(gallivm->builder,
+ "llvm.AMDGPU.kilp",
+ LLVMVoidTypeInContext(gallivm->context),
+ NULL, 0, 0);
+ }
+}
+
/* XXX: This is partially implemented for VS only at this point. It is not complete */
static void si_llvm_emit_epilogue(struct lp_build_tgsi_context * bld_base)
{
@@ -606,6 +638,10 @@
param_count++;
} else {
target = V_008DFC_SQ_EXP_MRT + color_count;
+ if (color_count == 0 &&
+ si_shader_ctx->key.alpha_func != PIPE_FUNC_ALWAYS)
+ si_alpha_test(bld_base, index);
+
color_count++;
}
break;