similar to: RFC: Adding 'no-overflow' keyword to 'sdiv'\'udiv' instructions

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

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

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 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

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

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

Hi guys, I just noticed that the LLVM has some node for signed/unsigned type( like udiv, sdiv), but why the ADD, SUB do not have the counter part sadd, uadd? best kevin

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

Hello, I want to know, if I can always assume that when I do unsigned operations like udiv, urem I will get the both operands converted to unsigned values? with under optimized version of code I sometimes receive these lines: unsigned a = 123; int b = -2; int c = a / b; -> %1 = udiv i32 123, -2 and get the result 0. Will it always be zero? or is it undefined?

I understand, but this sounds like legalization. Does every architecture trigger an overflow exception, as opposed to setting a bit? Perhaps it makes more sense to do this in the backends that trigger an overflow exception? I'm working on a modification for DIV right now in the x86 backend for Intel Atom that will improve performance, however because the *actual* operation has been replaced

hi, i'm new in R and i need some help. Please, ¿do you know a function how can process cross tables for many variables and show the result in one table who look like this?: +----------------------------------------------------+ |------------------ | X variable | |----------------- | Xop1 | Xop2 | Xop3|.....| +----------------------------------------------------+ |Yvar1 |

On Wed, Mar 29, 2017 at 2:15 PM, Friedman, Eli <efriedma at codeaurora.org> wrote: > On 3/29/2017 1:05 PM, Hongbin Zheng wrote: > >> Hi Eli, >> >> Thanks. Do you mean ideally we should extend SimplifyIndVar to do the >> sdiv->udiv replacement? >> > > I haven't really looked into it closely, but it seems to make sense. Ok. Once I extend

Our architecture has 1-bit boolean predicate registers. I've defined comparison def NErrb : InstTCE<(outs I1Regs:$op3), (ins I32Regs:$op1,I32Regs:$op2), "", [(set I1Regs:$op3, (setne I32Regs:$op1, I32Regs:$op2))]>; But then I end up having the following bug: Code %0 = zext i8 %data to i32 %1 = zext i16 %crc to i32 %2 = xor i32 %1, %0 %3 = and i32 %2, 1 %4 =

Hi LLVM, This is my idea I had some time ago, when I realized that LLVM did not support legalization of some arithmetic instructions like mul i256. I have implemented very simple and limited version of that in my project. Is it something LLVM users would appreciate? 1. The pass transforms IR and is meant to be run before CodeGen (after IR optimizations). 2. The pass replaces

Hi, in section B.29. (Write State Register Instructions) of 'The SPARC Architecture Manual Version 8' it is said that the "The write state register instructions are delayed-write instructions." The Y-register is a state-register. Furthermore in the B.29-secion there is a programming note saying: MULScc, RDY, SDIV, SDIVcc, UDIV, and UDIVcc implicitly read the Y register.

On Fri, Feb 7, 2020 at 12:29 PM Nuno Lopes <nunoplopes at sapo.pt> wrote: > > It's not correct (output of Alive2): > > define half @fn(half %a) { > %b = fadd half %a, undef > ret half %b > } > => > define half @fn(half %a) { > ret half undef > } > Transformation doesn't verify! > ERROR: Value mismatch > > Example: > half %a

Hello. I've managed to create a bitcode file (attached; also available at [1]) which produces a series of identical errors when verified: | Global variable initializer type does not match global variable type! | %i.NilClass* @nil When ran through llvm-dis and recompiled, through, it verifies successfully. If I disassemble it one more time, the result is identical to the first

I'm trying to implement *MUL_LOHI for my processor. My processor has mulxss (e.g.) that gives the 32 high bits of a 64 bit multiply. I tried this in ios2ISelDAGToDAG.cpp: /// Mul/Div with two results case ISD::SMUL_LOHI: case ISD::UMUL_LOHI: { SDValue Op1 = Node->getOperand(0); SDValue Op2 = Node->getOperand(1); AddToISelQueue(Op1);

Hi, Consider the following test case: int foo(float *A, float *B, float *C, int len, int VSMALL) { for (int i = 0; i < len; i++) if (C[i] > VSMALL) A[i] = B[i] / C[i]; } In this test the div operation is conditional but llvm is generating unconditional div for this case: vector.body: ; preds = %vector.body, %vector.ph %index = phi i64 [