search for: x86disassemblerdecod

there is an if-else code in X86DisassemblerDecoder.c that does exactly the same thing on both paths. so this patch removes the redundant path. thanks, Jun diff --git a/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c b/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c index 20e61da..3932ea1 100644 --- a/lib/Target/X86/Disassembler/X86Di...

Hi there! In the x86 disassembler I noticed an if-statement with a duplicated branch. Are these intended to be identical? Best regards, Nicolas Kaiser -- diff -ur llvm-2.8.orig/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c llvm-2.8/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c --- llvm-2.8.orig/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c 2010-05-06 22:59:00.000000000 +0200 +++ llvm-2.8/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c 2010-12-16 16:24:28.583323293 +0100 @@ -412,11 +412,6 @@...

Hi, In file X86DisassemblerDecoder.c, we have function readPrefixes() with below code: ..... } else if (insn->mode == MODE_32BIT) { insn->registerSize = (hasOpSize ? 2 : 4); insn->addressSize = (hasAdSize ? 2 : 4); insn->displacementSize = (hasAdSize ? 2 : 4); insn->immediateSize...

...ler design is a bit of a mess with regards to prefixes and operand size. On Tue, Apr 1, 2014 at 4:43 PM, Jun Koi <junkoi2004 at gmail.com> wrote: > > > > On Mon, Mar 31, 2014 at 11:48 PM, Jun Koi <junkoi2004 at gmail.com> wrote: > >> Hi, >> >> In file X86DisassemblerDecoder.c, we have function readPrefixes() with >> below code: >> >> ..... >> } else if (insn->mode == MODE_32BIT) { >> insn->registerSize = (hasOpSize ? 2 : 4); >> insn->addressSize = (hasAdSize ? 2 : 4); >> insn->displacem...

...b,0xc3"|./Release+Asserts/bin/llvm-mc -disassemble -triple=x86_64 .text <stdin>:1:1: warning: invalid instruction encoding 0x41,0x0f,0xeb,0xc3 ^ the last example should also return "por %mm3, %mm0", but it fails to understand the input. the reason stays with this line in X86DisassemblerDecoder.cpp: rm |= bFromREX(insn->rexPrefix) << 3; we can see that we take into account REX.B, but for "por" (0F EB), this should be ignored. there are quite a lot of other instructions taking into account REX like this, while according to the manual, REX should be ignored. i...

...xt >> <stdin>:1:1: warning: invalid instruction encoding >> 0x41,0x0f,0xeb,0xc3 >> ^ >> >> >> the last example should also return "por %mm3, %mm0", but it fails to >> understand the input. >> >> the reason stays with this line in X86DisassemblerDecoder.cpp: >> >> rm |= bFromREX(insn->rexPrefix) << 3; >> >> we can see that we take into account REX.B, but for "por" (0F EB), this >> should be ignored. >> >> there are quite a lot of other instructions taking into account REX like &gt...

...nalysis::Location&)': [off-opt] : [llvm] /ptmp/dag/llvm/official/llvm/lib/Analysis/AliasAnalysisCounter.cpp:165:15: error: 'MRString' may be used uninitialized in this function [-Werror=uninitialized] [off-opt] : [llvm] /ptmp/dag/llvm/official/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c: In function 'decode': [off-opt] : [llvm] /ptmp/dag/llvm/official/llvm/lib/Target/X86/Disassembler/X86DisassemblerDecoder.c:129:14: error: 'dec' may be used uninitialized in this function [-Werror=uninitialized] Note that these have to be optimized builds as the use-before-d...

hi, i found this code in X86DisassemblerDecoder.h #define EA_BASES_32BIT \ ENTRY(EAX) \ ENTRY(ECX) \ ENTRY(EDX) \ ENTRY(EBX) \ ENTRY(sib) \ ENTRY(EBP) \ ENTRY(ESI) \ ENTRY(EDI) \ ENTRY(R8D) \ ENTRY(R9D) \ ENTRY(...

.../Release+Asserts/bin/llvm-mc -disassemble >> -triple=x86_64 --output-asm-variant=1 >> .text >> <stdin>:1:1: warning: invalid instruction encoding >> 0x0f,0xc2,0xca,0x17 >> > > i am trying to figure out why this bug happens. according to the code in > X86DisassemblerDecoder.cpp, the last operand of CMPSS is checked against > TYPE_IMM5 (to be in the range [0, 31]), but i cannot find this TYPE_IMM5 > value anywhere in the definition of CMPSS, as below. > can somebody please enlighten me? > > thanks! > > // sse12_cmp_packed - sse 1 & 2 compare...

hi, some instructions mismatch between assembler & disassembler, like below. it seems this happens with all SSECC related instructions? thanks, Jun $ echo "cmpps xmm1, xmm2, 23" | ./Release+Asserts/bin/llvm-mc -assemble -triple=x86_64 --output-asm-variant=1 -x86-asm-syntax=intel -show-encoding .text cmpps xmm1, xmm2, 23 # encoding: [0x0f,0xc2,0xca,0x17] $

.../sample-binaries/README.md) might be the easiest way to inspect the patch code. > bcov depends on capstone, which appears to be a pretty standard disassembly > tool... It is based on a ~2013 shimmed-down version of LLVM MC and > LLVM*Disassembler. The generated files (e.g. > arch/X86/X86DisassemblerDecoder.c) > get ad-hoc sporadic amendment from contributors over the years.. It is a > bit > unfortunate for LLVM that MC and LLVM*Disassembler (Machine Code, including > assembly/disassembly libraries) cannot be easily adapted by downstream > users..... (Well, downstream packages can use...

## TL;DR We introduce bcov, an open-source binary-level coverage analysis tool [1]. The details are discussed in our paper [2], which is accepted to ESEC/FSE'20. bcov statically instruments x86-64 ELF binaries without compiler support. It features several techniques that allow it to achieve high performance, transparency, and flexibility. For example, running "make

...ctory '/home/NIKHILREDDY/WORK/LLVM_OBJ/lib/Target/X86/Disassembler' llvm[4]: Compiling X86Disassembler.cpp for Release+Asserts build llvm[3]: Compiling InstCombineVectorOps.cpp for Release+Asserts build llvm[3]: Building Release+Asserts Archive Library libLLVMAsmPrinter.a llvm[4]: Compiling X86DisassemblerDecoder.cpp for Release+Asserts build make[3]: Leaving directory '/home/NIKHILREDDY/WORK/LLVM_OBJ/lib/CodeGen/AsmPrinter' make[3]: Entering directory '/home/NIKHILREDDY/WORK/LLVM_OBJ/lib/CodeGen/MIRParser' llvm[3]: Compiling MILexer.cpp for Release+Asserts build llvm[3]: Compiling Instruc...