similar to: what is official way to determine if we are running lto 2nd stage?

Hi, In LTO we have AsmParser that process inline assembler instructions to MCInst and I want to fix some inline assembler in order to conform its rules (do not start with non-identifier and so on) because asm syntax of our backend allows some incompatible patterns. In order to do this I am adding IR-level target-specific pass. But those fixes shall not be applied when there is no AsmParser later

Hi, This is really basic block level pass. It is no difference what is level, problem is the same. After fixing for asm parser, assembler syntax is no more valid for backend, without processing with asm parser. May be it will be solution to process inline asm on insn printer level to remove syntax fixes. But just switch it off without lto will make compiler do less job P.S. sorry for dup,

Hi, Imagine that your backend has valid asm instruction written like this: "%x mnem %y, %z" And user puts it as inline assembler: __asm__ ("%x mnem %y, %z"); It can not be parsed with current llvm asm parser, because it starts with % (moreover it has mnemonic in second place) Say you written pass, that makes it "mnem %x, %y, %z". Now this guy can be parsed, but

Hi, Default register allocator tries to reuse the same registers over and over again even if register file have a plenty of registers to use. This creates parasite false dependencies and makes scheduling less effective. How to instruct allocator (may be override some virtual function in mine backend?) that it is profitable to use maximum number of available registers with minimal dependencies?

+Eric and Akira (for thoughts on module flags) > On 2016-Sep-16, at 12:47, Mehdi Amini <mehdi.amini at apple.com> wrote: > >> On Sep 16, 2016, at 12:30 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: >> >> In PR30403 we've been discussing how to encode -ffreestanding when using LTO. This bit is currently dropped during LTO because its only

Hi, Working on private backend, based on llvm-3.7 Inside lib/Transforms/InstCombine/InstCombineCompares.cpp there is attempt to optimize fabs: if (F->getIntrinsicID() == Intrinsic::fabs || ... switch (I.getPredicate()) { ... case FCmpInst::FCMP_OGT: return new FCmpInst(FCmpInst::FCMP_ONE, CI->getArgOperand(0), RHSC); But CI->getArgOperand(0)

(summarising IRC) Rethinking a little, I would be inclined to agree that combined hosted and freestanding modules should not be compiled in hosted mode. Here's one scenario where we may break: suppose I LTO-link an implementation of memset compiled with -ffreestanding with a program compiled with -fhosted. With the proposed rule, the loop idiom recognizer may transform the body of the memset

Hi, I am debugging private backend and faced interesting problem: sometimes spill hoisting creates double stores. (some output from -debug-only=regalloc). First hoisting: Checking redundant spills for 0 at 16r in %vreg19 [16r,144B:0)[144B,240B:1)[240B,280r:2)[296r,416B:3)[416B,456r:4)[472r,592B:5) 0 at 16r 1 at 144B-phi 2 at 240B-phi 3 at 296r 4 at 416B-phi 5 at 472r Merged to stack int: SS#0

Hi, Thanks for pointing direction. As far, as I understand by reversing, logic, that I want to overwrite is digged into: lib/MC/MCSectionELF.cpp MCSectionELF::PrintSwitchToSection if (ShouldOmitSectionDirective(SectionName, MAI)) { OS << '\t' << getSectionName() << '\n'; return; } // otherwise print ".section" directive and then section

In PR30403 we've been discussing how to encode -ffreestanding when using LTO. This bit is currently dropped during LTO because its only representation is in the TargetLibraryInfo created by clang ( http://llvm-cs.pcc.me.uk/tools/clang/lib/CodeGen/BackendUtil.cpp#258). The proposal is to introduce a module flag that we set in any translation unit compiled in hosted (i.e. -fno-freestanding)

Hi, In GCC there is one useful option -dp (or -dP for more verbose output) to annotate assembler with instruction patterns, that was used when assembler was generated. For example: double test(long long s) { return s; } gcc -S -dp -O0 test.c test: .LFB0: .cfi_startproc pushq %rbp # 18 *pushdi2_rex64/1 [length = 1] .cfi_def_cfa_offset 16 movq %rsp, %rbp # 19 *movdi_1_rex64/2

On Thu, Mar 15, 2012 at 11:00:54AM +0400, Konstantin Vladimirov wrote: > Hi, > > Thanks for pointing direction. As far, as I understand by reversing, > logic, that I want to overwrite is digged into: > > lib/MC/MCSectionELF.cpp > > MCSectionELF::PrintSwitchToSection > > if (ShouldOmitSectionDirective(SectionName, MAI)) { > OS << '\t'

On 2/16/2016 8:44 AM, Konstantin Vladimirov via llvm-dev wrote: > > CI->getArgOperand(0) returns operand with type (double*) rather then > double, because in our ABI doubles are passed via memory. The LLVM intrinsics in the LLVM IR must conform to whatever the IR's requirements are. That means that even in the case of your backend, the arguments to the intrinsic must be doubles,

On 02.03.2012, at 09:20, Konstantin Vladimirov wrote: > Hi, > > In GCC there is one useful option -dp (or -dP for more verbose output) > to annotate assembler with instruction patterns, that was used when > assembler was generated. For example: The internal "-mllvm -show-mc-inst" option is probably as close as you can get. $ clang -S -O0 test.c -mllvm -show-mc-inst -o

On Wed, Oct 28, 2020 at 6:07 PM Fangrui Song <maskray at google.com> wrote: > > On 2020-10-28, Alexandre Bique via llvm-dev wrote: > >Hi, > > > >I wonder what is the right way to target an old glibc? > > > >I have a machine which is up to date (glibc 2.32 and clang+lld 10.0.1). > > > >So far I've been able to target older glibc by having a

Hi Manman (and llvmdev), I filed these two bugs to track the ideas that I was cooking: http://llvm.org/bugs/show_bug.cgi?id=17891 http://llvm.org/bugs/show_bug.cgi?id=17892 TL;DR: I'm saying we should go from: !14 = metadata !{i32 786445, metadata !1, metadata !10, metadata !"y", i32 3, i64 32, i64 32, i64 32, i32 0, metadata !13} to: !14 = metadata

On Tue, Nov 12, 2013 at 4:14 PM, Chris Lattner <clattner at apple.com> wrote: > I'm moderately opposed to just encoding these in a string format. I think > we can do something substantially better both for space, time, and > readability. Fundamentally, there is no reason for the original metadata > node you describe to not *encode* its operands into a dense bit-packed blob

On Nov 12, 2013, at 1:28 PM, Chandler Carruth <chandlerc at google.com> wrote: > On Mon, Nov 11, 2013 at 11:29 PM, Chris Lattner <clattner at apple.com> wrote: > Hi Manman (and llvmdev), > > I filed these two bugs to track the ideas that I was cooking: > > http://llvm.org/bugs/show_bug.cgi?id=17891 > http://llvm.org/bugs/show_bug.cgi?id=17892 > > TL;DR:

On Mon, Nov 11, 2013 at 11:29 PM, Chris Lattner <clattner at apple.com> wrote: > Hi Manman (and llvmdev), > > I filed these two bugs to track the ideas that I was cooking: > > http://llvm.org/bugs/show_bug.cgi?id=17891 > http://llvm.org/bugs/show_bug.cgi?id=17892 > > TL;DR: I'm saying we should go from: > > !14 = metadata !{i32 786445, metadata !1,

[Adding llvm-dev and re-stating the situation for llvm-dev's benefit] *RFC: A new attribute, "norecurse".* In some cases, it is possible to demote global variables to local variables. This is possible when the global is only used in one function, and that function is known not to recurse (because if the function recurses, a local variable cannot be equivalent to a global as the