similar to: [LLVMdev] x86-64 sign extension for parameters and return values

On Wed, Feb 8, 2012 at 6:49 PM, Meador Inge <meadori at gmail.com> wrote: > I recently noticed a difference between the way GCC and LLVM treat > sign extension for parameters and return values on x86-64.  I could > not find a clear answer in the x86-64 ABI [1] concerning whether > parameters should be sign extended by the caller or callee and > similarly whether return values

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

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

Duncan Sands wrote: > Hi Nicolas, > > >> In order to have exceptions for non-call instructions (such as sdiv, >> load or stores), I'm modifying codegen so that it generates a BeginLabel >> and an EndLabel between the "may throwing" instruction. This is what the >> codegen of an InvokeInst does. >> > > the rule is that all

Hi Nicolas, > In order to have exceptions for non-call instructions (such as sdiv, > load or stores), I'm modifying codegen so that it generates a BeginLabel > and an EndLabel between the "may throwing" instruction. This is what the > codegen of an InvokeInst does. the rule is that all instructions between eh begin labelN and eh end labelN must unwind to the same

I attached preprocessed files. $ llvm-g++ gcc-RenderBoxModelObject.ii -fno-exceptions -arch x86_64 -O2 -c -o part.o vs $ clang++ clang-RenderBoxModelObject.ii -fno-exceptions -arch x86_64 -O2 -c -o part.o If I compile with clang, it causes a crash to webkit. -Argiris -------------- next part -------------- A non-text attachment was scrubbed... Name: prepro.zip Type: application/zip Size:

Hi everyone, In order to have exceptions for non-call instructions (such as sdiv, load or stores), I'm modifying codegen so that it generates a BeginLabel and an EndLabel between the "may throwing" instruction. This is what the codegen of an InvokeInst does. However, when generating native code, only BeginLabel is generated, and it is generated after the instruction. I'm not

On Thu, Feb 23, 2012 at 3:54 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > LLVM has traditionally assumed that all integer argument and return > types narrower than int are promoted to int on all architectures. > Nobody has actually noticed any issues with this before now, as far as > I know. The only reason that I noticed was that Python ctypes started misbehaving when

In testing build patches for gcc 4.8 to allow darwin to have asan support, I ran across a defect in mach_override/mach_override.c... http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55289#c27 which was solved with the patch proposed by Alexander Potapenko in... http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55289#c29 Index: mach_override.c

Hi All, The PRE or GVNPRE is not effective for the below use case. int sum; int phi =30; void f (int i, int *a) { if ((a[i] << (1)) > -15) sum =(phi+ 0x7fffffffL )/ a[i]; if ((a[i] << (2)) > -15) sum =(phi + 0x7fffffffL) /a[i]; } respective asm (clang on trunk ) #clang -O3 -S test.c BB#0: # %entry pushl %edi pushl %esi

Introduction: We would like to add new keyword to 'sdiv'\'udiv' instructions i.e. 'no-overflow'. This is the updated solution devised in the discussion: http://lists.llvm.org/pipermail/llvm-dev/2017-October/118257.html The proposed keywords: "nof" stands for 'no-overflow' Syntax: <result> = sdiv nof <ty> <op1>,

Hi llvm-dev, Looks like currently ScalarEvolution will give up if there is a sdiv in array subscript, e.g. int i; A[i * 64 / 2] in this case ScalarEvolution will just return an unknown for (i * 64 / 2). For this case, InstCombine will do the jobs, but in general, is there a pass to deal with the sdiv here? like replace sdiv by udiv based on the range of "i"? Thanks Hongbin

Hello LLVM-Dev, Attached are: · The DAG after being built · The DAG before the legalization phase The DAG illustrated performs a signed division for type i32. As can be seen, the SDIV node was converted to a series of other nodes (which includes a MULHS node). In the target lowering class of our target, the SDIV has an operation action of custom. Does anybody know where in

I've found what appears to be a bug in instcombine. Specifically, the transformation of -(X/C) to X/(-C) is invalid if C == INT_MIN. Specifically, if I have > define i32 @foo(i32 %x) #0 { > entry: > %div = sdiv i32 %x, -2147483648 > %sub = sub nsw i32 0, %div > ret i32 %sub > } then opt -instcombine will produce > define i32 @foo(i32 %x) #0 { > entry: > %sub

Introduction ========== We would like to add support for masked vector signed/unsigned integer division and remainder in the LLVM IR by introducing new target-independent intrinsics. This follows similar work which was done already for masked vector loads and stores - http://lists.llvm.org/pipermail/llvm-dev/2014-October/078059.html. Another relevant reference is the masked scatter/gather

add object rules so that the division, remainder and friends get really build on sparc, patch from Fabio M. Di Nitto <fabbione@ubuntu.com>. reworked to apply on latest git tree. Signed-off-by: maximilian attems <maks@sternwelten.at> --- Has been since long in the Debian and Ubuntu klibc. diff --git a/klibc/arch/sparc/Makefile.inc b/klibc/arch/sparc/Makefile.inc index

On Sun, 21 Sep 2014, Renato Golin wrote: > On 20 September 2014 15:19, Mikulas Patocka > <mikulas at artax.karlin.mff.cuni.cz> wrote: > > The problem is this - you either compile this program with > > -mcpu=cortex-a9, then clang reports error on the sdiv instruction because > > cortex a9 doesn't have sdiv. Or - you compile the program with > >

I was looking through the InstCombine pass, and I was wondering why signed division is not considered a valid operation to combine in the canEvaluateTruncated function. This means, given the following code: %conv = sext i16 %0 to i32 %conv1 = sext i16 %1 to i32 %div = sdiv i32 %conv, %conv1 %conv2 = trunc i32 %div to i16 * Assume %0 and %1 are registers created from simple 16-bit loads. We

I am trying to understand how LLVM does code generation and I have a couple of questions. I am using LLVM 2.6. First, if I want to change the name of an instruction, all I need to do is to modify the XXXInstrInfo.td, right? Using Sparc as an example, if I wanted to output "mysra" instead of "sra", in SparcInstrInfo.td, I would write, defm SRA : F3_12<"mysra",

Hi Eli, Thanks. Do you mean ideally we should extend SimplifyIndVar to do the sdiv->udiv replacement? Thanks Hongbin On Wed, Mar 29, 2017 at 10:59 AM, Friedman, Eli <efriedma at codeaurora.org> wrote: > On 3/29/2017 10:35 AM, Hongbin Zheng via llvm-dev wrote: > >> Hi llvm-dev, >> >> Looks like currently ScalarEvolution will give up if there is a sdiv in