+struct ac_build_if_state
+{
+ struct radv_shader_context *ctx;
+ LLVMValueRef condition;
+ LLVMBasicBlockRef entry_block;
+ LLVMBasicBlockRef true_block;
+ LLVMBasicBlockRef false_block;
+ LLVMBasicBlockRef merge_block;
+};
+
+static LLVMBasicBlockRef
+ac_build_insert_new_block(struct radv_shader_context *ctx, const char *name)
+{
+ LLVMBasicBlockRef current_block;
+ LLVMBasicBlockRef next_block;
+ LLVMBasicBlockRef new_block;
+
+ /* get current basic block */
+ current_block = LLVMGetInsertBlock(ctx->ac.builder);
+
+ /* chqeck if there's another block after this one */
+ next_block = LLVMGetNextBasicBlock(current_block);
+ if (next_block) {
+ /* insert the new block before the next block */
+ new_block = LLVMInsertBasicBlockInContext(ctx->context, next_block, name);
+ }
+ else {
+ /* append new block after current block */
+ LLVMValueRef function = LLVMGetBasicBlockParent(current_block);
+ new_block = LLVMAppendBasicBlockInContext(ctx->context, function, name);
+ }
+ return new_block;
+}
+
+static void
+ac_nir_build_if(struct ac_build_if_state *ifthen,
+ struct radv_shader_context *ctx,
+ LLVMValueRef condition)
+{
+ LLVMBasicBlockRef block = LLVMGetInsertBlock(ctx->ac.builder);
+
+ memset(ifthen, 0, sizeof *ifthen);
+ ifthen->ctx = ctx;
+ ifthen->condition = condition;
+ ifthen->entry_block = block;
+
+ /* create endif/merge basic block for the phi functions */
+ ifthen->merge_block = ac_build_insert_new_block(ctx, "endif-block");
+
+ /* create/insert true_block before merge_block */
+ ifthen->true_block =
+ LLVMInsertBasicBlockInContext(ctx->context,
+ ifthen->merge_block,
+ "if-true-block");
+
+ /* successive code goes into the true block */
+ LLVMPositionBuilderAtEnd(ctx->ac.builder, ifthen->true_block);
+}
+
+/**
+ * End a conditional.
+ */
+static void
+ac_nir_build_endif(struct ac_build_if_state *ifthen)
+{
+ LLVMBuilderRef builder = ifthen->ctx->ac.builder;
+
+ /* Insert branch to the merge block from current block */
+ LLVMBuildBr(builder, ifthen->merge_block);
+
+ /*
+ * Now patch in the various branch instructions.
+ */
+
+ /* Insert the conditional branch instruction at the end of entry_block */
+ LLVMPositionBuilderAtEnd(builder, ifthen->entry_block);
+ if (ifthen->false_block) {
+ /* we have an else clause */
+ LLVMBuildCondBr(builder, ifthen->condition,
+ ifthen->true_block, ifthen->false_block);
+ }
+ else {
+ /* no else clause */
+ LLVMBuildCondBr(builder, ifthen->condition,
+ ifthen->true_block, ifthen->merge_block);
+ }
+
+ /* Resume building code at end of the ifthen->merge_block */
+ LLVMPositionBuilderAtEnd(builder, ifthen->merge_block);
+}
+
+