similar to: Inline assembly in intel syntax mishandling i constraint

> On Jan 7, 2020, at 18:41, Craig Topper <craig.topper at gmail.com> wrote: > > What version of llvm are you using? This looks like it may be fixed on trunk. After poking at my installation of rust, I'm not entirely sure what version of LLVM it uses. Looking at the GitHub page, it looks like Rust maintains their own copy of llvm and cherry picks commits. The C example was

Hi all, I'm trying to land (a rebased version of) http://llvm.org/D37461 - which should make it possible to handle x86 Intel assembly like mov eax, offset Foo::ptr + 1 (Currently, omitting the +1 works... but offset doesn't work in compound expressions.) I'm having trouble figuring out what inline assembly I can emit into the LLVM IR that will work properly. So far, the closest

Hi all, I'm working for translating dex bytecode to LLVM IR In order to communicate with Android interpreter, The work have to add data below some instructions I want to use inline assembly to add data. Thus, I wrote a little program to find out the related LLVM IR int main() { asm(".long 0x12345678"); return 0; } and I use clang to translate it into bitcode It's the

I encountered this issue of unique asm label names just now, in https://bugs.freebsd.org/216771 . A very simple test case is this: void foo(void) { asm volatile( "named_label:\n" "jnz named_label\n" ); } void bar(void) { foo(); } Compiling this with any form of optimization gives an error, because clang is attempting to inline foo() into

Hey all, I'd like to propose a new intrinsic for use in preventing optimizations from deleting IR due to constant propagation, dead code elimination, etc. # Background/Motivation In Rust we have a crate called `test` which provides a function, `black_box`, which is designed to be a no-op function that prevents constprop, die, etc from interfering with tests/benchmarks but otherwise

Dear, Can anybody comment on inserting inline assembly in LLVM IR? -- Pratik -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140620/03400e95/attachment.html>

Eli Friedman wrote: > 2009/8/2 Richard Pennington <rich at pennware.com>: >> The following fails on x86_64 because of the output constraint '0'. >> My question is, is this legal. LLVM complains about the size difference >> (32 vs 64), but it is the same register (ax). >> Works on x86. >> >> %42 = call i64 asm sideeffect

The following fails on x86_64 because of the output constraint '0'. My question is, is this legal. LLVM complains about the size difference (32 vs 64), but it is the same register (ax). Works on x86. %42 = call i64 asm sideeffect "syscall\0A\09", "={ax},0,{di},~{dirflag},~{fpsr},~{flags}"(i64 231, i64 %41) nounwind ; <i64> [#uses=2] -Rich

Using Clang/LLVM 3.6.0 we are observing a case where the optimizations are clobbering EFLAGS on x86_64. This is inconvenient when the status of bit 9 (IF), which controls interrupts, changes. Here's a simple test program. Assume that the external function foo() modifies the IF bit in EFLAGS. --- #include <stdlib.h> #include <stdbool.h> void foo(void); int a; int bar(void)

HI, When compiling the open-source software cryptopp (https://www.cryptopp.com/#download <https://www.cryptopp.com/#download>) version 5.6.4 I found a strange issue with the IR generated. The issue only appears when compiling with -O2 optimisation in the integer.cpp file (the function is _ZN8CryptoPPrsERNSt3__113basic_istreamIcNS0_11char_traitsIcEEEERNS_7IntegerE ->

Hi, I' am trying to insert an InlineAsm Instruction in my pass, which FunctionType do I need for Inlineasm? If I understand it right, I need a call instruction to insert the new produced InlineAsm? Thanks for help, Michael for (BasicBlock::iterator bi = i->begin(), be = i->end(); bi != be; ++bi){ std::vector<const Type*> asm_arguments;

2009/8/2 Richard Pennington <rich at pennware.com>: > Eli Friedman wrote: >> 2009/8/2 Richard Pennington <rich at pennware.com>: >>> The following fails on x86_64 because of the output constraint '0'. >>> My question is, is this legal. LLVM complains about the size difference >>> (32 vs 64), but it is the same register (ax). >>>

2009/8/2 Richard Pennington <rich at pennware.com>: > The following fails on x86_64 because of the output constraint '0'. > My question is, is this legal. LLVM complains about the size difference > (32 vs 64), but it is the same register (ax). > Works on x86. > > %42 = call i64 asm sideeffect "syscall\0A\09", >

On Jul 31, 2009, at 10:24 AM, Michael Graumann wrote: > Hi, > I’ am trying to insert an InlineAsm Instruction in my pass, which > FunctionType do I need for Inlineasm? > If I understand it right, I need a call instruction to insert the > new produced InlineAsm? > > Thanks for help Inline asm works like a "callee". So for: call void asm sideeffect

Hi, I would like to prevent that two adjacent calls to external functions getting interleaved/separated by other neighboring code. This mixing seems to happen in the code generator. I can prevent it by putting the two calls into a separate BB, but then I can't use -simplifycfg, -jump-threading, ... as is. Here is an example: %160 = add i64 %158, %159 ; <i64>

I remember this bug. :) IMO, LLVM should never emit pushf / popf. I'm not sure this patch to fix it ever got committed: http://reviews.llvm.org/D6629 On Wed, Jul 29, 2015 at 3:11 PM, Michael Hordijk <hoffbrinkle at hotmail.com> wrote: > > Using Clang/LLVM 3.6.0 we are observing a case where the optimizations are > clobbering EFLAGS on x86_64. This is inconvenient when the

Hello, Most of the IR language is correctly explained; but with inline assembly I feel alone at some point: define i32 @main(i32 %argc, i8** %argv) #0 { ... //some uninteresting bloat here call void asm sideeffect "outw %eax, $0", "imr,~{dirflag},~{fpsr},~{flags}"(i32 %8) #2, !srcloc !2 ret i32 0 } I reduced the above code to the offending line containing:

Hello, In the following code snippet: %tmp49 = call i64 asm "movq %gs:${1:P},$0", "=r,im,,~{fpsr},~{flags}"(i64* @kernel_stack) #6, !dbg !6625, !srcloc !5841 I would expect for the inline asm call to receive two arguments because of the ${1:P} corresponding to a %P1 that will append the $1 to %%gs:. Can someone explain why there is only one argument in this call? Moreover,

Interesting - the patch doesn't address this yet. It looks like we have a difference (maybe bug?) in how we handle Intel vs. AT&T inline assembly: https://godbolt.org/z/GQw9ED Suppose we're expanding an operand with an 'i' constraint, where the operand is given as, e.g. (i32* @Bar). If the inline assembly is in Intel dialect, this expands as "Bar" in AT&T syntax

Are there any examples for the inline assembler or more complete docs? Questions: * What are the syntax and semantics of constraints? * If I load up specific registers in the inline assembly, will llvm make sure that those registers are unassigned or should I save the registers and restore them? i.e. does llvm try and understand what is going on in the inline assembly, or is it a black box to