From 172f68e1e53ca4e98c161e7b6d80c990173f4e2e Mon Sep 17 00:00:00 2001
From: Andrea Shepard <andrea@persephoneslair.org>
Date: Wed, 23 Nov 2016 07:35:32 +0000
Subject: [PATCH] Handle h_bits() in LLVM backend
---
src/parsers/bits.c | 96 +++++++++++++++-------------------------------
1 file changed, 30 insertions(+), 66 deletions(-)
diff --git a/src/parsers/bits.c b/src/parsers/bits.c
index 159a20dd..bd9fa8e0 100644
--- a/src/parsers/bits.c
+++ b/src/parsers/bits.c
@@ -27,74 +27,38 @@ static HParseResult* parse_bits(void* env, HParseState *state) {
#ifdef HAMMER_LLVM_BACKEND
static bool bits_llvm(HLLVMParserCompileContext *ctxt, void* env) {
+ /* Emit LLVM IR to parse ((struct bits_env *)env)->length bits */
+
if (!ctxt) return false;
- /* %result = alloca %struct.HParsedToken_*, align 8 */
- #pragma GCC diagnostic push
- #pragma GCC diagnostic ignored "-Wunused-variable"
- LLVMValueRef result = LLVMBuildAlloca(ctxt->builder, ctxt->llvm_parsedtoken, "result");
- #pragma GCC diagnostic pop
- /* store i8* %env, i8** %1, align 8 */
- /* store %struct.HParseState_* %state, %struct.HParseState_** %2, align 8 */
- /* %3 = load i8** %1, align 8 */
- /* %4 = bitcast i8* %3 to %struct.bits_env* */
- /* store %struct.bits_env* %4, %struct.bits_env** %env, align 8 */
- /* %5 = load %struct.HParseState_** %2, align 8 */
- /* %6 = getelementptr inbounds %struct.HParseState_* %5, i32 0, i32 2 */
- /* %7 = load %struct.HArena_** %6, align 8 */
- /* %8 = call noalias i8* @h_arena_malloc(%struct.HArena_* %7, i64 48) */
- /* %9 = bitcast i8* %8 to %struct.HParsedToken_* */
- /* store %struct.HParsedToken_* %9, %struct.HParsedToken_** %result, align 8 */
- /* %10 = load %struct.bits_env** %env_, align 8 */
- /* %11 = getelementptr inbounds %struct.bits_env* %10, i32 0, i32 1 */
- /* %12 = load i8* %11, align 1 */
- /* %13 = zext i8 %12 to i32 */
- /* %14 = icmp ne i32 %13, 0 */
- /* %15 = select i1 %14, i32 4, i32 8 */
- /* %16 = load %struct.HParsedToken_** %result, align 8 */
- /* %17 = getelementptr inbounds %struct.HParsedToken_* %16, i32 0, i32 0 */
- /* store i32 %15, i32* %17, align 4 */
- /* %18 = load %struct.bits_env** %env_, align 8 */
- /* %19 = getelementptr inbounds %struct.bits_env* %18, i32 0, i32 1 */
- /* %20 = load i8* %19, align 1 */
- /* %21 = icmp ne i8 %20, 0 */
- /* br i1 %21, label %22, label %33 */
-
- /* ; <label>:22 ; preds = %0 */
- /* %23 = load %struct.HParseState_** %2, align 8 */
- /* %24 = getelementptr inbounds %struct.HParseState_* %23, i32 0, i32 1 */
- /* %25 = load %struct.bits_env** %env_, align 8 */
- /* %26 = getelementptr inbounds %struct.bits_env* %25, i32 0, i32 0 */
- /* %27 = load i8* %26, align 1 */
- /* %28 = zext i8 %27 to i32 */
- /* %29 = call i64 @h_read_bits(%struct.HInputStream_* %24, i32 %28, i8 signext 1) */
- /* %30 = load %struct.HParsedToken_** %result, align 8 */
- /* %31 = getelementptr inbounds %struct.HParsedToken_* %30, i32 0, i32 1 */
- /* %32 = bitcast %union.anon* %31 to i64* */
- /* store i64 %29, i64* %32, align 8 */
- /* br label %44 */
-
- /* ; <label>:33 ; preds = %0 */
- /* %34 = load %struct.HParseState_** %2, align 8 */
- /* %35 = getelementptr inbounds %struct.HParseState_* %34, i32 0, i32 1 */
- /* %36 = load %struct.bits_env** %env_, align 8 */
- /* %37 = getelementptr inbounds %struct.bits_env* %36, i32 0, i32 0 */
- /* %38 = load i8* %37, align 1 */
- /* %39 = zext i8 %38 to i32 */
- /* %40 = call i64 @h_read_bits(%struct.HInputStream_* %35, i32 %39, i8 signext 0) */
- /* %41 = load %struct.HParsedToken_** %result, align 8 */
- /* %42 = getelementptr inbounds %struct.HParsedToken_* %41, i32 0, i32 1 */
- /* %43 = bitcast %union.anon* %42 to i64* */
- /* store i64 %40, i64* %43, align 8 */
- /* br label %44 */
-
- /* ; <label>:44 ; preds = %33, %22 */
- /* %45 = load %struct.HParseState_** %2, align 8 */
- /* %46 = getelementptr inbounds %struct.HParseState_* %45, i32 0, i32 2 */
- /* %47 = load %struct.HArena_** %46, align 8 */
- /* %48 = load %struct.HParsedToken_** %result, align 8 */
- /* %49 = call %struct.HParseResult_* @make_result(%struct.HArena_* %47, %struct.HParsedToken_* %48) */
- /* ret %struct.HParseResult_* %49 */
+ struct bits_env *env_ = env;
+ /* Error out on unsupported length */
+ if (env_->length > 64 || env_->length == 0) return false;
+ /* Set up params for call to h_read_bits */
+ LLVMValueRef bits_args[3];
+ bits_args[0] = ctxt->stream;
+ bits_args[1] = LLVMConstInt(LLVMInt32Type(), env_->length, 0);
+ bits_args[2] = LLVMConstInt(LLVMInt8Type(), env_->signedp ? 1 : 0, 0);
+
+ /* Set up basic blocks: entry, success and failure branches, then exit */
+ LLVMBasicBlockRef bits_bb = LLVMAppendBasicBlock(ctxt->func, "bits");
+
+ /* Basic block: entry */
+ LLVMBuildBr(ctxt->builder, bits_bb);
+ LLVMPositionBuilderAtEnd(ctxt->builder, bits_bb);
+
+ /* Call to h_read_bits() */
+ // %read_bits = call i64 @h_read_bits(%struct.HInputStream_* %8, i32 env_->length, i8 signext env_->signedp)
+ LLVMValueRef bits = LLVMBuildCall(ctxt->builder,
+ LLVMGetNamedFunction(ctxt->mod, "h_read_bits"), bits_args, 3, "read_bits");
+
+ /* Make an HParseResult out of it */
+ LLVMValueRef mr;
+ h_llvm_make_tt_suint(ctxt, env_->length, env_->signedp, bits, &mr);
+
+ /* Return mr */
+ LLVMBuildRet(ctxt->builder, mr);
+
return true;
}
--
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