[Mesa-dev] [PATCH 3/3] ac: make use of if/loop build helpers

[Timothy Arceri]

These helpers insert the basic block in the same order as they
appear in NIR making it easier to follow LLVM IR dumps. The helpers
also insert more useful labels onto the blocks.

TGSI use the line number of the corresponding opcode in the TGSI
dump as the label id, here we use the corresponding block index
from NIR.
---
 src/amd/common/ac_nir_to_llvm.c | 60 +++++++++++++----------------------------
 1 file changed, 18 insertions(+), 42 deletions(-)

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index cda91fe8bf..dc463ed253 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -5237,17 +5237,15 @@ static void visit_ssa_undef(struct ac_nir_context *ctx,
 	_mesa_hash_table_insert(ctx->defs, &instr->def, undef);
 }
 
-static void visit_jump(struct ac_nir_context *ctx,
+static void visit_jump(struct ac_llvm_context *ctx,
 		       const nir_jump_instr *instr)
 {
 	switch (instr->type) {
 	case nir_jump_break:
-		LLVMBuildBr(ctx->ac.builder, ctx->break_block);
-		LLVMClearInsertionPosition(ctx->ac.builder);
+		ac_build_break(ctx);
 		break;
 	case nir_jump_continue:
-		LLVMBuildBr(ctx->ac.builder, ctx->continue_block);
-		LLVMClearInsertionPosition(ctx->ac.builder);
+		ac_build_continue(ctx);
 		break;
 	default:
 		fprintf(stderr, "Unknown NIR jump instr: ");
@@ -5285,7 +5283,7 @@ static void visit_block(struct ac_nir_context *ctx, nir_block *block)
 			visit_ssa_undef(ctx, nir_instr_as_ssa_undef(instr));
 			break;
 		case nir_instr_type_jump:
-			visit_jump(ctx, nir_instr_as_jump(instr));
+			visit_jump(&ctx->ac, nir_instr_as_jump(instr));
 			break;
 		default:
 			fprintf(stderr, "Unknown NIR instr type: ");
@@ -5302,56 +5300,34 @@ static void visit_if(struct ac_nir_context *ctx, nir_if *if_stmt)
 {
 	LLVMValueRef value = get_src(ctx, if_stmt->condition);
 
-	LLVMValueRef fn = LLVMGetBasicBlockParent(LLVMGetInsertBlock(ctx->ac.builder));
-	LLVMBasicBlockRef merge_block =
-	    LLVMAppendBasicBlockInContext(ctx->ac.context, fn, "");
-	LLVMBasicBlockRef if_block =
-	    LLVMAppendBasicBlockInContext(ctx->ac.context, fn, "");
-	LLVMBasicBlockRef else_block = merge_block;
-	if (!exec_list_is_empty(&if_stmt->else_list))
-		else_block = LLVMAppendBasicBlockInContext(
-		    ctx->ac.context, fn, "");
-
-	LLVMValueRef cond = LLVMBuildICmp(ctx->ac.builder, LLVMIntNE, value,
-	                                  ctx->ac.i32_0, "");
-	LLVMBuildCondBr(ctx->ac.builder, cond, if_block, else_block);
-
-	LLVMPositionBuilderAtEnd(ctx->ac.builder, if_block);
+	nir_block *then_block =
+		(nir_block *) exec_list_get_head(&if_stmt->then_list);
+
+	ac_build_uif(&ctx->ac, value, then_block->index);
+
 	visit_cf_list(ctx, &if_stmt->then_list);
-	if (LLVMGetInsertBlock(ctx->ac.builder))
-		LLVMBuildBr(ctx->ac.builder, merge_block);
 
 	if (!exec_list_is_empty(&if_stmt->else_list)) {
-		LLVMPositionBuilderAtEnd(ctx->ac.builder, else_block);
+		nir_block *else_block =
+			(nir_block *) exec_list_get_head(&if_stmt->else_list);
+
+		ac_build_else(&ctx->ac, else_block->index);
 		visit_cf_list(ctx, &if_stmt->else_list);
-		if (LLVMGetInsertBlock(ctx->ac.builder))
-			LLVMBuildBr(ctx->ac.builder, merge_block);
 	}
 
-	LLVMPositionBuilderAtEnd(ctx->ac.builder, merge_block);
+	ac_build_endif(&ctx->ac, then_block->index);
 }
 
 static void visit_loop(struct ac_nir_context *ctx, nir_loop *loop)
 {
-	LLVMValueRef fn = LLVMGetBasicBlockParent(LLVMGetInsertBlock(ctx->ac.builder));
-	LLVMBasicBlockRef continue_parent = ctx->continue_block;
-	LLVMBasicBlockRef break_parent = ctx->break_block;
+	nir_block *first_loop_block =
+		(nir_block *) exec_list_get_head(&loop->body);
 
-	ctx->continue_block =
-	    LLVMAppendBasicBlockInContext(ctx->ac.context, fn, "");
-	ctx->break_block =
-	    LLVMAppendBasicBlockInContext(ctx->ac.context, fn, "");
+	ac_build_bgnloop(&ctx->ac, first_loop_block->index);
 
-	LLVMBuildBr(ctx->ac.builder, ctx->continue_block);
-	LLVMPositionBuilderAtEnd(ctx->ac.builder, ctx->continue_block);
 	visit_cf_list(ctx, &loop->body);
 
-	if (LLVMGetInsertBlock(ctx->ac.builder))
-		LLVMBuildBr(ctx->ac.builder, ctx->continue_block);
-	LLVMPositionBuilderAtEnd(ctx->ac.builder, ctx->break_block);
-
-	ctx->continue_block = continue_parent;
-	ctx->break_block = break_parent;
+	ac_build_endloop(&ctx->ac, first_loop_block->index);
 }
 
 static void visit_cf_list(struct ac_nir_context *ctx,
-- 
2.14.3