similar to: RFC: Pass for lowering "non-linear" arithmetics of illegal types

Displaying 20 results from an estimated 2000 matches similar to: "RFC: Pass for lowering "non-linear" arithmetics of illegal types"

2006 Apr 18
1
[patch] sparc build fix
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
2018 Dec 16
2
LLC Version 3.8 : Unsupported library call operation for a mul instruction
Hello List, I am on the hook to instrument a piece of legacy LLVM IR code, and then we are planning to feed to the SeaHorn framework for some model checking tasks. After the instrumentation, I tried to use llc (version 3.9) to compile the IR code, and it works fine. However, when I try to use llc (version 3.8.1, the default llvm version of SeaHorn) to compile the IR code, it shows the following
2008 Mar 31
3
[LLVMdev] Reference Manual Clarifications
Here are some clarifications for the reference manual. Please verify that my assumptions are correct. Shall I post a patch? Floating-point Constants: Add "The assembler requires the exact decimal value of a floating-point constant. For example, the assembler accepts '1.25' but rejects '1.3' because '1.3' is a repeating decimal in binary." Binary
2020 Feb 07
2
Why does FPBinOp(X, undef) -> NaN?
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
2018 Sep 25
2
Unsafe floating point operation (FDiv & FRem) in LoopVectorizer
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 [
2013 Jun 21
0
[LLVMdev] ExpandDivRemLibCall vs. AEABI
Hi Renato, > * Have some call-back mechanism, possibly upon a flag > (HasSpecialDivRemLowering), and update the remainder result If you setOperationAction on SDIVREM and UDIVREM to Custom you can expand the rtlib call appropriately yourself. There's precedent for sincos on Darwin systems (both ARM and x86) and in AArch64 for basically every operation on fp128. Cheers. Tim.
2013 Jun 21
3
[LLVMdev] ExpandDivRemLibCall vs. AEABI
Folks, I'm working on bug 16387: "clang doesn't produce ARM EABI-compliant modulo runtime function" http://llvm.org/bugs/show_bug.cgi?id=16387 And I need some pointers. I've changed ARMISelLowering::ARMTargetLowering::ARMTargetLowering() to associate __aeabi_idivmod variants to RTLIB::{U,S}DIVREM_* library calls, but now I need to teach the expansion that on AEABI case,
2017 Jul 31
4
unsigned operations with negative numbers
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?
2014 Apr 24
4
[LLVMdev] Proposal: add intrinsics for safe division
Hi, I’d like to propose to extend LLVM IR intrinsics set, adding new ones for safe-division. There are intrinsics for detecting overflow errors, like sadd.with.overflow, and the intrinsics I’m proposing will augment this set. The new intrinsics will return a structure with two elements according to the following rules: safe.[us]div(x,0) = safe.[us]rem(x,0) = {0, 1} safe.sdiv(min<T>, -1) =
2010 Mar 12
0
[LLVMdev] Smaller than 32-bit?
Hi Russell- The PIC16 is an 8-bit target, and the msp430 is a 16-bit target. The rules about the largest supported integer no longer apply as much- for most operations, codegen can now handle arbitrary precision (exceptions: mul, udiv, urem, sdiv, srem). For those five, library calls should be emitted for big integers - best way to check if they're supported is to just try them :) Alastair
2008 Aug 22
3
[LLVMdev] Implementing llvm.memory.barrier on PowerPC
No, I don't. Cheers, Gary Dale Johannesen wrote: > This looks OK to check in, do you have write access? > > On Aug 21, 2008, at 6:38 AMPDT, Gary Benson wrote: > > >Dale Johannesen wrote: > >>On Aug 19, 2008, at 7:18 AMPDT, Gary Benson wrote: > >>>I'm trying to implement llvm.memory.barrier on PowerPC. I've > >>>modelled my patch
2008 Aug 19
2
[LLVMdev] Implementing llvm.memory.barrier on PowerPC
Hi all, I'm trying to implement llvm.memory.barrier on PowerPC. I've modelled my patch (attached) on the implementation in X86, but when I try and compile my test file (also attached) with llc I get the error "Cannot yet select: 0x10fa4ad0: ch = MemBarrier 0x10fa4828, 0x10fa4c68, 0x10fa4be0, 0x10fa4be0, 0x10fa4be0, 0x10fa4be0". This presumably means my "membarrier"
2010 Mar 11
2
[LLVMdev] Smaller than 32-bit?
Does LLVM support any target platforms on which the natural integer size/pointer size is smaller than 32 bits? For example, I noticed mention of PIC16, is that such a platform? If so, does the usual rule about the largest supported integer being the size of two pointers still apply? So that on that platform you can't use 64-bit integers, but you can use 32-bit integers?
2013 Nov 18
1
[LLVMdev] Modular arithmetic processors
Thanks for your insightful suggestions. Yes, I am programming for a real device that does modular arithmetic (and only modular arithmetic). The modulus N is fixed during a single launch of a program. One way I could also come up with is to simply use add i256 %a, %b to represent a + b mod n, and let LLVM passes to reason about possible optimizations. However these are not semantically identical
2018 Dec 14
2
LLVM Error: Unsupported library call operation
Hello, I am on the hook to instrument a piece of legacy LLVM IR code, and then we are planning to feed to the SeaHorn framework for some model checking tasks. After the instrumentation, I tried to use llc (version 3.9) to compile the IR code, and it works fine. However, when I try to use llc (version 3.8.1, the default llvm version of SeaHorn) to compile the IR code, it shows the following
2013 Nov 15
2
[LLVMdev] Modular arithmetic processors
I've been playing around with LLVM to write a backend for a rather "simple" (co-)processor. Assume that only three arithmetic instructions exist: ADD mod N, SUB mod N and MUL mod N. The modulus N is programmable and stored in a register. No ordinary arithmetic instructions are available. The word size is 256-bit. In other words, the following function, b + c mod N, corresponds to
2008 Aug 21
2
[LLVMdev] Implementing llvm.memory.barrier on PowerPC
Dale Johannesen wrote: > On Aug 19, 2008, at 7:18 AMPDT, Gary Benson wrote: > > I'm trying to implement llvm.memory.barrier on PowerPC. I've > > modelled my patch (attached) on the implementation in X86, but > > when I try and compile my test file (also attached) with llc I > > get the error "Cannot yet select: 0x10fa4ad0: ch = MemBarrier > >
2013 Nov 15
0
[LLVMdev] Modular arithmetic processors
Hi, My personal opinion: Just to be sure I understand what you're considering: you want to write a backend that will produce optimized machine code for a device with modular arithmetic instructions (not simulate such a device on a standard CPU)? In which case, won't the same assumptions that are embodied in the transformations for the case of unsigned 2's complement arithmetic (in
2019 Mar 21
2
Signed Div SCEVs
Hi, I am working with SCEVs, I see the unsigned division of SCEVs, it is not immediately clear to me why the signed division of SCEV expressions is not supported by SE? I would appreciate if some could clarify or point me to some links. -- Regards, DTharun -------------- next part -------------- An HTML attachment was scrubbed... URL:
2014 Apr 25
4
[LLVMdev] Proposal: add intrinsics for safe division
On April 25, 2014 at 9:52:35 AM, Eric Christopher (echristo at gmail.com) wrote: Hi Michael, > I’d like to propose to extend LLVM IR intrinsics set, adding new ones for > safe-division. There are intrinsics for detecting overflow errors, like > sadd.with.overflow, and the intrinsics I’m proposing will augment this set. > > The new intrinsics will return a structure with two