[Mesa-dev] [PATCH 08/19] gallium/radeon: clean up emit_declaration for temporaries

[Nicolai Hähnle]

From: Nicolai Hähnle <nicolai.haehnle at amd.com>

In the alloca'd array case, no longer create redundant and unused allocas
for the individual elements; create getelementptrs instead.
---
 .../drivers/radeon/radeon_setup_tgsi_llvm.c        | 27 ++++++++++++++--------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
index d75311e..41f24d3 100644
--- a/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
+++ b/src/gallium/drivers/radeon/radeon_setup_tgsi_llvm.c
@@ -408,81 +408,90 @@ static LLVMValueRef si_build_alloca_undef(struct gallivm_state *gallivm,
 	LLVMValueRef ptr = lp_build_alloca(gallivm, type, name);
 	LLVMBuildStore(gallivm->builder, LLVMGetUndef(type), ptr);
 	return ptr;
 }
 
 static void emit_declaration(struct lp_build_tgsi_context *bld_base,
 			     const struct tgsi_full_declaration *decl)
 {
 	struct radeon_llvm_context *ctx = radeon_llvm_context(bld_base);
 	LLVMBuilderRef builder = bld_base->base.gallivm->builder;
-	unsigned first, last, i, idx;
+	unsigned first, last, i;
 	switch(decl->Declaration.File) {
 	case TGSI_FILE_ADDRESS:
 	{
 		 unsigned idx;
 		for (idx = decl->Range.First; idx <= decl->Range.Last; idx++) {
 			unsigned chan;
 			for (chan = 0; chan < TGSI_NUM_CHANNELS; chan++) {
 				 ctx->soa.addr[idx][chan] = si_build_alloca_undef(
 					&ctx->gallivm,
 					ctx->soa.bld_base.uint_bld.elem_type, "");
 			}
 		}
 		break;
 	}
 
 	case TGSI_FILE_TEMPORARY:
 	{
+		LLVMValueRef array_alloca = NULL;
 		unsigned decl_size;
 		first = decl->Range.First;
 		last = decl->Range.Last;
 		decl_size = 4 * ((last - first) + 1);
 		if (decl->Declaration.Array) {
 			unsigned id = decl->Array.ArrayID - 1;
 			if (!ctx->arrays) {
 				int size = bld_base->info->array_max[TGSI_FILE_TEMPORARY];
 				ctx->arrays = CALLOC(size, sizeof(ctx->arrays[0]));
-			for (i = 0; i < size; ++i) {
-				assert(!ctx->arrays[i].alloca);}
 			}
 
 			ctx->arrays[id].range = decl->Range;
 
 			/* If the array is more than 16 elements (each element
 			 * is 32-bits), then store it in a vector.  Storing the
 			 * array in a vector will causes the compiler to store
 			 * the array in registers and access it using indirect
 			 * addressing.  16 is number of vector elements that
 			 * LLVM will store in a register.
 			 * FIXME: We shouldn't need to do this.  LLVM should be
 			 * smart enough to promote allocas int registers when
 			 * profitable.
 			 */
 			if (decl_size > 16) {
-				ctx->arrays[id].alloca = LLVMBuildAlloca(builder,
+				array_alloca = LLVMBuildAlloca(builder,
 					LLVMArrayType(bld_base->base.vec_type, decl_size),"array");
+				ctx->arrays[id].alloca = array_alloca;
 			}
 		}
-		first = decl->Range.First;
-		last = decl->Range.Last;
+
 		if (!ctx->temps_count) {
 			ctx->temps_count = bld_base->info->file_max[TGSI_FILE_TEMPORARY] + 1;
 			ctx->temps = MALLOC(TGSI_NUM_CHANNELS * ctx->temps_count * sizeof(LLVMValueRef));
 		}
-		for (idx = first; idx <= last; idx++) {
-			for (i = 0; i < TGSI_NUM_CHANNELS; i++) {
-				ctx->temps[idx * TGSI_NUM_CHANNELS + i] =
+		if (!array_alloca) {
+			for (i = 0; i < decl_size; ++i) {
+				ctx->temps[first * TGSI_NUM_CHANNELS + i] =
 					si_build_alloca_undef(bld_base->base.gallivm,
 							      bld_base->base.vec_type,
 							      "temp");
 			}
+		} else {
+			LLVMValueRef idxs[2] = {
+				bld_base->uint_bld.zero,
+				NULL
+			};
+			for (i = 0; i < decl_size; ++i) {
+				idxs[1] = lp_build_const_int32(bld_base->base.gallivm, i);
+				ctx->temps[first * TGSI_NUM_CHANNELS + i] =
+					LLVMBuildGEP(builder, array_alloca, idxs, 2, "temp");
+			}
 		}
 		break;
 	}
 	case TGSI_FILE_INPUT:
 	{
 		unsigned idx;
 		for (idx = decl->Range.First; idx <= decl->Range.Last; idx++) {
 			if (ctx->load_input)
 				ctx->load_input(ctx, idx, decl);
 		}
-- 
2.7.4