similar to: unnecessary reload of 8-byte struct on i386

Hmm, I'm not able to get those .ll files to compile if I disable SSE and I end up with SSE instructions(including sqrtpd) if I don't disable it. On Thu, Jul 18, 2013 at 10:53 PM, Peter Newman <peter at uformia.com> wrote: > Is there something specifically required to enable SSE? If it's not > detected as available (based from the target triple?) then I don't think

Compiling a simple automaton created by GNU bison with -O1 or -O2 resulted in the following machine code: 1300 /*-----------------------------. 1301 | yyreduce -- Do a reduction. | 1302 `-----------------------------*/ 1303 yyreduce: 1304 /* yyn is the number of a rule to reduce with. */ 1305 yylen = yyr2[yyn]; 0x0000000000400c14 <rpcalc_parse+628>: mov

Hi, We seem to have found a bug in the LLVM 3.8 code generator. We are using MCJIT and have isolated working.ll and broken.ll after middle-end optimizations -- in the block merge128, notice that broken.ll has a fcmp une comparison to zero and a jump based on that branch: merge128: ; preds = %true71, %false72 %_rtB_724 = load %B_repro_T*, %B_repro_T**

Hi, I have run into the following strange behavior and wanted to ask for some advice. For the C program below, function sum() gets inlined in foo() but the code generated looks very suboptimal (the code is an extract from a larger program). Below I show the 32-bit x86 assembly as produced by the demo page on the llvm home page ("Output A"). As you can see from the assembly, after

I don't know much about this, but maybe -mllvm -unroll-count=1 can be used as a workaround? /Patrik Hägglund -----Original Message----- From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Brent Walker Sent: den 28 mars 2012 03:18 To: llvmdev Subject: [LLVMdev] Suboptimal code due to excessive spilling Hi, I have run into the following strange behavior

Hi, I'm compiling lldiv.c from the NetBSD standard library. It works on ARM, Mips, Microblaze,ppc, ppc64, and x86_64. On i386 a very strange thing happens. Here's the source: #include <stdlib.h> #define __weak_alias(sym) __attribute__ ((weak, alias (#sym))) lldiv_t lldiv(long long int num, long long int denom) __weak_alias(_lldiv); lldiv_t _lldiv(long long num, long

The limitation with the "Reviewed by" line is that if you just use `arc` it indicates who was added as reviewer on the revision, but not who approved it. Because of this, I am wary of relying on this line for anything. If you want to know who reviewed a change, better click on the Differential Revision link and go to the source of truth. -- Mehdi On Thu, Jan 2, 2020 at 10:44 AM

Objects compiled for the MS-ABI don't conform to it! Data types beyond 64 bit MUST BE returned by the callee via the hidden first argument allocated by the caller, NOT in XMM0! Demo/proof: from this source --- llvm-bug.c --- #ifndef __clang__ typedef struct { unsigned __int64 low; unsigned __int64 high; } __uint128_t; #else __attribute__((ms_abi)) #endif __uint128_t

I'm sure I've seen many commits with both "Reviewed by:" and "Reviewers:" tags, which look to have been done with arc (though I can't be sure). How were those generated? On Sat, 4 Jan 2020 at 19:12, David Blaikie <dblaikie at gmail.com> wrote: > Yeah, I tend to prune it down myself - and if the list has only one name > on it, it's usually a pretty

I also find the "Reviewed by" tag useful (as well as the review link), for the same reasons. In fact, I don't even use arcanist to push commits, so I do it all by hand, and only include the "Reviewed by" and "Differential Revision" tags. On Fri, 27 Dec 2019 at 20:55, David Blaikie via llvm-dev < llvm-dev at lists.llvm.org> wrote: > I don't think

Hi, In GCC there is one useful option -dp (or -dP for more verbose output) to annotate assembler with instruction patterns, that was used when assembler was generated. For example: double test(long long s) { return s; } gcc -S -dp -O0 test.c test: .LFB0: .cfi_startproc pushq %rbp # 18 *pushdi2_rex64/1 [length = 1] .cfi_def_cfa_offset 16 movq %rsp, %rbp # 19 *movdi_1_rex64/2

Introduction ----------------- Currently llvm-mca only accepts assembly code as input. We would like to extend llvm-mca to support object files, allowing users to analyze the performance of binaries. The proposed changes (which involve both clang and llvm) optionally introduce an object file section, but this can be stripped-out if desired. For the llvm-mca binary support feature to be useful, a

I write a small function and test it under clang and gcc, filet test.c: double X[100]; double Y[100]; double DA = 0.3; int f() { int i; for (i = 0; i < 100; i++) Y[i] = Y[i] - DA * X[i]; return 0; } clang -S -O3 -o test.s test.c -march=native -ccc-echo result: "D:/work/trunk/bin/Release/clang.exe" -cc1 -triple i686-pc-win32 -S -disable-fr e -disable-llvm-verifier

On 10/30/20 4:51 PM, Pawel Winogrodzki wrote: > Hello, > > We are currently trying to apply a patch to our 8.0p1 version of OpenSSH for CVE-2020-14145<https://nvd.nist.gov/vuln/detail/CVE-2020-14145>. The "patch" tag from NIST's web page links to the 8.3p1 vs 8.4p1 comparison<https://github.com/openssh/openssh-portable/compare/V_8_3_P1...V_8_4_P1> on GitHub. Is

I sent a long message yesterday describing a problem I thought had to do with the JIT stubs. After further investigating, the problem seems to be in the code generation. The following basic block seems to have an error in it's code generation: __exp.exit: ; preds = %codeRepl258, %__exp_bb_bb.exit phi double [ 1.000000e+00, %codeRepl258 ], [ %.reload.reload.i,

Hi all, I'm trying to insert a function call "llvm_memory_profiling " right before each memory access. The function uses the effective address of the memory access as its single parameter. A example is as follows: the function call at 402a99 has a parameter passed to %rdi at 402a91. One can see that the function call is exactly before the memory access I want to monitor because

Hey guys, I'm working on a bug for x86-64 in LLVM 2.9. Well, it's actually two issues. The assembly generated for large stack offsets has an overflow; And, once the overflow is fixed, the displacement is too large for GNU ld to handle it. void fool( int long n ) { double w[268435600]; double z[268435600]; unsigned long i; for ( i = 0; i < n; i++ ) { w[i] = 1.0; z[i] =

On Wed, Oct 12, 2016 at 10:53 AM, Hal Finkel <hfinkel at anl.gov> wrote: > I don't think that Clang/LLVM uses it by default on x86_64. If you're using -Ofast, however, that would explain it. I recommend looking at -O3 vs -O0 and make sure those are the same. -Ofast enables -ffast-math, which can legitimately cause differences. > The following tests pass at "-O3" and

Hi Andrea, Thanks for your input. On Wed, Nov 21, 2018 at 12:43:52PM +0000, Andrea Di Biagio wrote: [... snip ...] > About the suggested design: > I like the idea of being able to identify code regions using a numeric > identifier. > However, what happens if a code region spans through multiple basic blocks? The current patch does not take into consideration cases where the region

On 02.03.2012, at 09:20, Konstantin Vladimirov wrote: > Hi, > > In GCC there is one useful option -dp (or -dP for more verbose output) > to annotate assembler with instruction patterns, that was used when > assembler was generated. For example: The internal "-mllvm -show-mc-inst" option is probably as close as you can get. $ clang -S -O0 test.c -mllvm -show-mc-inst -o