similar to: [LLVMdev] Trouble with inline asm

Displaying 20 results from an estimated 8000 matches similar to: "[LLVMdev] Trouble with inline asm"

2008 Jun 06
0
[LLVMdev] Trouble with inline asm
On Fri, Jun 6, 2008 at 6:32 AM, Tomas Lindquist Olsen <tomas.l.olsen at gmail.com> wrote: > Hi all, > > I'm having some trouble with inline asm expressions, more specifically > how to create the right FunctionType for a given constraint set. > So far it has worked well for inputs, but not for outputs. The inline > asm support in this language (which is D, LLVMDC[1]) is
2008 Jun 07
1
[LLVMdev] Trouble with inline asm
On Fri, Jun 6, 2008 at 9:29 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Fri, Jun 6, 2008 at 6:32 AM, Tomas Lindquist Olsen > <tomas.l.olsen at gmail.com> wrote: >> Hi all, >> >> I'm having some trouble with inline asm expressions, more specifically >> how to create the right FunctionType for a given constraint set. >> So far it has
2016 Jun 30
4
Help required regarding IPRA and Local Function optimization
Hello Mentors, I am currently finding bug in Local Function related optimization due to which runtime failures are observed in some test cases, as those test cases are containing very large function with recursion and object oriented code so I am not able to find a pattern which is causing failure. So I tried following simple case to understand expected behavior from this optimization. Consider
2009 Jul 31
0
[LLVMdev] Inserting Instructions (pass)
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
2009 Jul 31
2
[LLVMdev] Inserting Instructions (pass)
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;
2020 Jan 07
2
Inline assembly in intel syntax mishandling i constraint
Hi all, I'm getting rather odd behavior from a call asm inteldialect(). TL;DR is "mov reg, $0" with a "i" constraint on $0 is behaving identical to "mov reg, dword ptr [$0]" and differently from "movl $0, reg" in AT&T syntax. I'm not sure how to get clang to emit an inteldialect, so for this example, I'm emitting llvm and then modifying
2020 Jan 08
2
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
2016 Jun 28
2
Instruction selection problem with type i64 - mistaken as v8i64?
Hello. I am writing a back end in which I combined the existing BPF LLVM back end with the Mips MSA vector extensions (from the Mips back end) I have encountered an error when compiling with llc: the instruction selector uses a vector register instead of a scalar register with type i64 . I have the following part of LLVM IR program: vector.body.preheader:
2016 Jul 21
2
InlineAsm and allocation to wrong register for indirect access
Hi, I am seeing a case, in a private port, of an inline asm with indirect memory references being allocated invalid registers (i.e. registers that cannot be used on loads). For example, the inline asm constraint is correct: call void asm sideeffect "MOV $$r0, $0\0AMOV $$r0, $1\0A", "*m,*m,~{r0}"(i16* @a, i16* %b) #1, !srcloc !1 but then $0 and $1 are allocated to registers
2005 Feb 22
5
[LLVMdev] Area for improvement
I noticed that fourinarow is one of the programs in which LLVM is much slower than GCC, so I decided to take a look and see why that is so. The program has many loops that look like this: #define ROWS 6 #define COLS 7 void init_board(char b[COLS][ROWS+1]) { int i,j; for (i=0;i<COLS;i++) for (j=0;j<ROWS;j++) b[i][j]='.';
2019 Dec 09
4
IR inline assembly: the x86 Intel "offset" operator
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
2010 Sep 01
5
[LLVMdev] equivalent IR, different asm
The attached .ll files seem equivalent, but the resulting asm from 'opt-fail.ll' causes a crash to webkit. I suspect the usage of registers is wrong, can someone take a look ? $ llc opt-pass.ll -o - .section __TEXT,__text,regular,pure_instructions .globl __ZN7WebCore6kolos1ERiS0_PKNS_20RenderBoxModelObjectEPNS_10StyleImageE .align 4, 0x90
2005 Feb 22
0
[LLVMdev] Area for improvement
When I increased COLS to the point where the loop could no longer be unrolled, the selection dag code generator generated effectively the same code as the default X86 code generator. Lots of redundant imul/movl/addl sequences. It can't clean it up either. Only unrolling all nested loops permits it to be optimized away, regardless of code generator. Jeff Cohen wrote: > I noticed
2011 Dec 14
0
[LLVMdev] Failure to optimize ? operator
On Tue, Dec 13, 2011 at 5:59 AM, Brent Walker <brenthwalker at gmail.com> wrote: > The following seemingly identical functions, get compiled to quite > different machine code.  The first is correctly optimized (the > computation of var y is nicely moved into the else branch of the "if" > statement), which the second one is not (the full computation of var y > is
2010 Mar 16
3
[LLVMdev] LLVM-GCC generating too much code from inline assembly
Hi, I recently switched to LLVM-GCC 4.2 on OS X, to go around a bug caused by gcc with optimized code. Unfortunately, I ran into another weird problem on LLVM-GCC. In my code, there's a file with a bunch of inline assembly blocks, that worked fine with GCC 4.2. Now, when compiling with LLVM-GCC 4.2, weird things happen. Here's an example: (the blocks are larger than that, but a single
2011 Dec 14
2
[LLVMdev] Failure to optimize ? operator
I don't understand your point. Which version is better does NOT depend on what inputs are passed to the function. The compiled code for (as per llvm) f1 will always take less time to execute than f2. for x > 0 => T(f1) < T(f2) for x <= 0 => T(f1) = T(f2) where T() is the time to execute the given function. So always T(f1) <= T(f2). I would call this a missed
2017 Aug 04
2
Bug or incorrect use of inline asm?
On Thu, Aug 3, 2017 at 6:19 PM, Tim Northover <t.p.northover at gmail.com> wrote: > 2017-08-03 8:58 GMT-07:00 Johan Engelen via llvm-dev < > llvm-dev at lists.llvm.org>: > > The error is gone after removing (or reducing) the alignment of `%a`. > This > > makes me believe that our inline asm syntax is correct to add an offset > to a > > pointer: "
2010 Sep 01
0
[LLVMdev] equivalent IR, different asm
On Sep 1, 2010, at 6:25 AM, Argyrios Kyrtzidis wrote: > The attached .ll files seem equivalent, but the resulting asm from 'opt-fail.ll' causes a crash to webkit. > I suspect the usage of registers is wrong, can someone take a look ? The difference is that there is a shift right after the multiply, before the divide. In IR, the difference is: %5 = mul nsw i32 %4, %tmp1
2016 Oct 29
1
Problems with Inline ASM expressions generated in the back end
Hello. I generated in the back end by hand (in C++ code, not with TableGen) some fancy assembly code using Inline ASM expressions and if I use 2 functions in my source code (but NOT just 1 function; I will not present the functions, but each requires me to generate an Inline ASM expression) I get this error at compilation (at scheduling): BB#0: derived from LLVM BB %entry
2011 Dec 13
4
[LLVMdev] Failure to optimize ? operator
The following seemingly identical functions, get compiled to quite different machine code. The first is correctly optimized (the computation of var y is nicely moved into the else branch of the "if" statement), which the second one is not (the full computation of var y is always done). The output was produced using the demo page on llvm's web site (optimization level LTO). Can