From e70d7ad28ad1cd1e00dfe32ccbad1732ae97cb27 Mon Sep 17 00:00:00 2001
From: Andrea Shepard <andrea@persephoneslair.org>
Date: Wed, 9 Nov 2016 20:43:37 +0000
Subject: [PATCH] Clean up comments/formatting in ch_llvm()
---
src/parsers/ch.c | 106 ++++++++++++++++++++++++-----------------------
1 file changed, 54 insertions(+), 52 deletions(-)
diff --git a/src/parsers/ch.c b/src/parsers/ch.c
index 9d680077..65b951d7 100644
--- a/src/parsers/ch.c
+++ b/src/parsers/ch.c
@@ -47,101 +47,103 @@ static bool ch_ctrvm(HRVMProg *prog, void* env) {
}
static bool ch_llvm(LLVMBuilderRef builder, LLVMValueRef func, LLVMModuleRef mod, void* env) {
- uint8_t c_ = (uint8_t)(uintptr_t)(env);
- LLVMValueRef c = LLVMConstInt(LLVMInt8Type(), c_, 0);
- /* LLVMTypeRef param_types[] = { */
- /* llvm_inputstream, */
- /* llvm_arena */
- /* }; */
- /* LLVMTypeRef ret_type = LLVMFunctionType(llvm_parseresultptr, param_types, 2, 0); */
- /* LLVMValueRef ch = LLVMAddFunction(mod, "ch", ret_type); */
- // get the parameter array to use later with h_bits
+ // Build a new LLVM function to parse a character
+
+ // Set up params for calls to h_read_bits() and h_arena_malloc()
LLVMValueRef bits_args[3];
- // LLVMGetParams(ch, bits_args);
LLVMValueRef stream = LLVMGetFirstParam(func);
stream = LLVMBuildBitCast(builder, stream, llvm_inputstreamptr, "stream");
bits_args[0] = stream;
bits_args[1] = LLVMConstInt(LLVMInt32Type(), 8, 0);
bits_args[2] = LLVMConstInt(LLVMInt8Type(), 0, 0);
- // LLVMValueRef arena = LLVMGetParam(ch, 1);
LLVMValueRef arena = LLVMGetLastParam(func);
- // LLVMBasicBlockRef entry = LLVMAppendBasicBlock(ch, "ch_entry");
+
+ // Set up basic blocks: entry, success and failure branches, then exit
LLVMBasicBlockRef entry = LLVMAppendBasicBlock(func, "ch_entry");
- // LLVMBasicBlockRef success = LLVMAppendBasicBlock(ch, "ch_success");
LLVMBasicBlockRef success = LLVMAppendBasicBlock(func, "ch_success");
- // LLVMBasicBlockRef fail = LLVMAppendBasicBlock(ch, "ch_fail");
LLVMBasicBlockRef fail = LLVMAppendBasicBlock(func, "ch_fail");
- // LLVMBasicBlockRef end = LLVMAppendBasicBlock(ch, "ch_end");
LLVMBasicBlockRef end = LLVMAppendBasicBlock(func, "ch_end");
+
+ // Basic block: entry
LLVMPositionBuilderAtEnd(builder, entry);
- // %1 = alloca %struct.HParseResult_*, align 8
+ // Allocate stack space for our return value
+ // %ret = alloca %struct.HParseResult_*, align 8
LLVMValueRef ret = LLVMBuildAlloca(builder, llvm_parseresultptr, "ret");
- // skip %2 through %c because we have these from arguments, and %r because we'll get it later
- // skip %tok (we'll bitcast it later) through %8
- // %9 = call i64 @h_read_bits(%struct.HInputStream_* %8, i32 8, i8 signext 0)
+
+ // Call to h_read_bits()
+ // %read_bits = call i64 @h_read_bits(%struct.HInputStream_* %8, i32 8, i8 signext 0)
LLVMValueRef bits = LLVMBuildCall(builder, LLVMGetNamedFunction(mod, "h_read_bits"), bits_args, 3, "read_bits");
- // %10 = trunc i64 %9 to i8
+ // %2 = trunc i64 %read_bits to i8
LLVMValueRef r = LLVMBuildTrunc(builder, bits, LLVMInt8Type(), ""); // do we actually need this?
- // %11 = load i8* %c
- // %12 = zext i8 %11 to i32
- // %13 = load i8* %r, align 1
- // %14 = zext i8 %13 to i32
- // %15 = icmp eq i32 %12, %14
+
+ // Check if h_read_bits succeeded
+ // %"c == r" = icmp eq i8 -94, %2 ; the -94 comes from c_
+ uint8_t c_ = (uint8_t)(uintptr_t)(env);
+ LLVMValueRef c = LLVMConstInt(LLVMInt8Type(), c_, 0);
LLVMValueRef icmp = LLVMBuildICmp(builder, LLVMIntEQ, c, r, "c == r");
- // br i1 %15, label %16, label %34
+
+ // Branch so success or failure basic block, as appropriate
+ // br i1 %"c == r", label %ch_success, label %ch_fail
LLVMBuildCondBr(builder, icmp, success, fail);
- // ; <label>:16 - success case
+ // Basic block: success
LLVMPositionBuilderAtEnd(builder, success);
- // skip %17-%19 because we have the arena as an argument
+
+ // Set up call to h_arena_malloc() for a new HParsedToken
LLVMValueRef tok_size = LLVMConstInt(LLVMInt32Type(), sizeof(HParsedToken), 0);
LLVMValueRef amalloc_args[] = { arena, tok_size };
- // %20 = call noalias i8* @h_arena_malloc(%struct.HArena_* %19, i64 48)
+ // %h_arena_malloc = call void* @h_arena_malloc(%struct.HArena_.1* %1, i32 48)
LLVMValueRef amalloc = LLVMBuildCall(builder, LLVMGetNamedFunction(mod, "h_arena_malloc"), amalloc_args, 2, "h_arena_malloc");
- // %21 = bitcast i8* %20 to %struct.HParsedToken_*
+ // %3 = bitcast void* %h_arena_malloc to %struct.HParsedToken_.2*
LLVMValueRef tok = LLVMBuildBitCast(builder, amalloc, llvm_parsedtokenptr, "");
- // store %struct.HParsedToken_* %21, %struct.HParsedToken_** %tok, align 8
- // LLVMBuildStore(builder, cast1, tok);
-
- // %22 = load %struct.HParsedToken_** %tok, align 8
- // %23 = getelementptr inbounds %struct.HParsedToken_* %22, i32 0, i32 0
+ // tok->token_type = TT_UINT;
+ //
+ // %token_type = getelementptr inbounds %struct.HParsedToken_.2, %struct.HParsedToken_.2* %3, i32 0, i32 0
LLVMValueRef toktype = LLVMBuildStructGEP(builder, tok, 0, "token_type");
- // store i32 8, i32* %23, align 4
+ // store i32 8, i32* %token_type
LLVMBuildStore(builder, LLVMConstInt(LLVMInt32Type(), 8, 0), toktype);
- // %24 = load i8* %r, align 1
- // %25 = zext i8 %24 to i64
- // %26 = load %struct.HParsedToken_** %tok, align 8
- // %27 = getelementptr inbounds %struct.HParsedToken_* %26, i32 0, i32 1
- // %28 = bitcast %union.anon* %27 to i64*
+
+ // tok->uint = r;
+ //
+ // %token_data = getelementptr inbounds %struct.HParsedToken_.2, %struct.HParsedToken_.2* %3, i32 0, i32 1
LLVMValueRef tokdata = LLVMBuildStructGEP(builder, tok, 1, "token_data");
- LLVMBuildStore(builder, LLVMBuildZExt(builder, r, LLVMInt64Type(), "r"), tokdata); // do we actually need the zext, or can we just use the 'bits' value from line 82?
+ // %r = zext i8 %2 to i64
+ // store i64 %r, i64* %token_data
+ LLVMBuildStore(builder, LLVMBuildZExt(builder, r, LLVMInt64Type(), "r"), tokdata);
+ // %t_index = getelementptr inbounds %struct.HParsedToken_.2, %struct.HParsedToken_.2* %3, i32 0, i32 2
LLVMValueRef tokindex = LLVMBuildStructGEP(builder, tok, 2, "t_index");
+ // %s_index = getelementptr inbounds %struct.HInputStream_.0, %struct.HInputStream_.0* %0, i32 0, i32 2
LLVMValueRef streamindex = LLVMBuildStructGEP(builder, stream, 2, "s_index");
+ // %4 = load i64, i64* %s_index
+ // store i64 %4, i64* %t_index
LLVMBuildStore(builder, LLVMBuildLoad(builder, streamindex, ""), tokindex);
LLVMValueRef tokbitlen = LLVMBuildStructGEP(builder, tok, 3, "bit_length");
LLVMBuildStore(builder, LLVMConstInt(LLVMInt64Type(), 8, 0), tokbitlen);
- // we already have the arena and the token, so skip to %33
- // %33 = call %struct.HParseResult_* @make_result(%struct.HArena_* %31, %struct.HParsedToken_* %32)
+
+ // Now call make_result()
+ // %make_result = call %struct.HParseResult_.3* @make_result(%struct.HArena_.1* %1, %struct.HParsedToken_.2* %3)
LLVMValueRef result_args[] = { arena, tok };
LLVMValueRef mr = LLVMBuildCall(builder, LLVMGetNamedFunction(mod, "make_result"), result_args, 2, "make_result");
- // store %struct.HParseResult_* %33, %struct.HParseResult_** %ret
+
+ // Store for return
+ // store %struct.HParseResult_.3* %make_result, %struct.HParseResult_.3** %ret
LLVMBuildStore(builder, mr, ret);
- // br label %35
+ // br label %ch_end
LLVMBuildBr(builder, end);
- // ; <label>:34 - failure case
+ // Basic block: failure
LLVMPositionBuilderAtEnd(builder, fail);
- // store %struct.HParseResult* null, %struct.HParseResult_** %ret
+ // store %struct.HParseResult_.3* null, %struct.HParseResult_.3** %ret
LLVMBuildStore(builder, LLVMConstNull(llvm_parseresultptr), ret);
- // br label %35
+ // br label %ch_end
LLVMBuildBr(builder, end);
- // ; <label>:35
+ // Basic block: end
LLVMPositionBuilderAtEnd(builder, end);
- // %rv = load %struct.HParseResult_** %ret
+ // %rv = load %struct.HParseResult_.3*, %struct.HParseResult_.3** %ret
LLVMValueRef rv = LLVMBuildLoad(builder, ret, "rv");
- // ret %struct.HParseResult_* %rv
+ // ret %struct.HParseResult_.3* %rv
LLVMBuildRet(builder, rv);
return true;
}
--
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