similar to: [ARM] Thumb code-gen for 8-bit imm arguments results in extra reg copies

On Tue, 16 Jun 2020 at 15:47, Tim Northover <t.p.northover at gmail.com> wrote: > > On Tue, 16 Jun 2020 at 10:23, Prathamesh Kulkarni via llvm-dev > <llvm-dev at lists.llvm.org> wrote: > > (b) Modifies RegisterCoalescer::reMaterializeTrivialDef and > > TargetInstrInfo::isReallyTriviallyReMaterializableGeneric to check > > for single live def, instead of

On Wed, 15 Apr 2020 at 03:36, John Brawn <John.Brawn at arm.com> wrote: > > > Could you please point out what am I doing wrong in the patch ? > > It's because you're getting the function name by doing > callee->getName().str().c_str() > The str() call generates a temporary copy of the name which ceases to exist outside of this expression > causing the

Hi, I have attached WIP patch for adding foldMemoryOperand to Thumb1InstrInfo. For the following case: void f(int x, int y, int z) { void bar(int, int, int); bar(x, y, z); bar(x, z, y); bar(y, x, z); bar(y, y, x); } it calls foldMemoryOperand twice, and thus converts two calls from blx to bl. callMI->dump() shows the function name "bar" correctly, however in generated

On Sep 4, 2010, at 5:40 PM, Eli Friedman wrote: > If you want to take a look at this yourself, the issue is easy to > reproduce with Thumb1: Thanks, Eli. Nice catch! This IR: target triple = "thumbv5-u-u" define arm_aapcscc i64 @foo(i64 %a, i64 %b) nounwind readnone { entry: %xor = xor i64 %a, 18 ; <i64> [#uses=1] %xor2 = xor i64 %xor, %b

Hi, Compiling attached test-case, which is reduced version of of uECC_shared_secret from tinycrypt library [1], with --target=arm-linux-gnueabi -march=armv6-m -Oz -S results in reloading of register holding function's address before every call to blx: ldr r3, .LCPI0_0 blx r3 mov r0, r6 mov r1, r5 mov r2, r4 ldr r3,

If I'm understanding what's going on in this test correctly, what's happening is: * ARMTargetLowering::LowerCall prefers indirect calls when a function is called at least 3 times in minsize * In thumb 1 (without -fno-omit-frame-pointer) we have effectively only 3 callee-saved registers (r4-r6) * The function has three arguments, so those three plus the register we need to hold the

Hello LLVM Developers, We are working on extending currently available register rematerialization to include cases where sequence of multiple instructions is required to rematerialize a value. We had a discussion on this in community mailing list and link is here: http://lists.llvm.org/pipermail/llvm-dev/2016-September/subject.html#104777 >From the above discussion and studying the code we

On Sat, Sep 4, 2010 at 1:31 PM, Jakob Stoklund Olesen <stoklund at 2pi.dk> wrote: > > On Sep 4, 2010, at 11:21 AM, Borja Ferrer wrote: > >> I've noticed this pattern happening with other operators aswell, but used xor in this example. As i said before, i tried with different register allocation orders, but it will produce always the same result. GCC is emitting longer

I see strangeness on Thumb TST (tTST) predicate 'isCompare' It is true for regular ARM, false for Thumb: (gdb) p MI->dump() TSTri %reg16397, 3, pred:14, pred:%reg0, %CPSR<imp-def>; GPR:% reg16397 $24 = void (gdb) p MI->getDesc().isCompare() $25 = true (gdb) p MI->dump() tTST %reg16396, %reg16397, pred:14, pred:%reg0, %CPSR<imp-def>; tGPR:%reg16396,16397

On Sep 14, 2010, at 12:09 PM, Gabor Greif wrote: > I see strangeness on Thumb TST (tTST) predicate 'isCompare' > > It is true for regular ARM, false for Thumb: > > (gdb) p MI->dump() > TSTri %reg16397, 3, pred:14, pred:%reg0, %CPSR<imp-def>; GPR:% > reg16397 > $24 = void > (gdb) p MI->getDesc().isCompare() > $25 = true > > > (gdb)

Hi Quentin, I get following error from MachineVerifier: # End machine code for function f. *** Bad machine code: Missing mayLoad flag *** which comes from: // Check the MachineMemOperands for basic consistency. for (MachineMemOperand *Op : MI->memoperands()) { if (Op->isLoad() && !MI->mayLoad()) report("Missing mayLoad flag", MI); if (Op->isStore()

Hi, While working on https://reviews.llvm.org/D79785, we wanted to define foldMemoryOperandImpl hook for Thumb1, that folds load, indirect call to direct call tLDRpci, tBLX -> tBL. This triggered an assertion error with expensive checks turned on in MachineVerifier because the newly created tBL insn by Thumb1InstrInfo::foldMemoryOperandImpl had memory operands of LoadMI attached by

On Sep 4, 2010, at 11:21 AM, Borja Ferrer wrote: > I've noticed this pattern happening with other operators aswell, but used xor in this example. As i said before, i tried with different register allocation orders, but it will produce always the same result. GCC is emitting longer code, but since LLVM is so nearer to the optimal code sequence i wanted to reach it. In LLVM, copies are

Hi Craig, Thanks for the information. Can you point to the source that specifies tGPR to be R0 - R7? I tried to search in ARMInstrThumb.td but couldn’t find it. Thanks, - Jie On Apr 14, 2019, at 15:28, Craig Topper <craig.topper at gmail.com<mailto:craig.topper at gmail.com>> wrote: I believe there is probably a separate instruction in LLVM for thumb2 add. Probably starting with t2

I'm working on an out-of-tree target and am having some problems with rematerialization and spilling. The target's load and store instructions affect the condition code register (CCR). Describing this in the InstrInfo.td file using Defs = [CCR] certainly prevents spills and fills from being inserted where they might clobber CCR but it also prevents the load instruction from being

Reed, On May 14, 2012, at 3:45 PM, reed kotler <rkotler at mips.com> wrote: > On 05/14/2012 02:42 PM, Jakob Stoklund Olesen wrote: >> On May 14, 2012, at 2:28 PM, reed kotler wrote: >> >>> I'm not using getMinimalPhysRegClass. Some target independent code is using it. >> Probably PEI. >> >>> It makes trouble for us and I would like to

Hi, All, I want to lower 64 Bits constant such as 'long' and 'double'. So I define them like this: def CONSTI64 : InstFOO<(outs GRWideRegs:$dst), (ins i64imm:$src), "const-long $dst, $src", [(set (i64 GRWideRegs:$dst), imm:$src)]>{ let isMoveImm = 1; } def CONSTF64 : InstFOO<(outs

The code has changed a lot over the years. Looks like at some point of time the assumption was broken. calculateCallsInformation() may have eliminated the pseudo set up instructions already. // If call frames are not being included as part of the stack frame, and

Thanks, I'll look into that. Still, the case where the function does not call anything remains---in such a situation there are no ADJCALLSTACK pseudos, so regardless of what that function you pointed at does, there won't be any target-independent information about the SP adjustment by the time the frame index elimination runs. Would it make sense to have ADJCALLSTACK pseudos every

On Jun 3, 2013, at 6:05 AM, Steve Montgomery <stephen.montgomery3 at btinternet.com> wrote: > I'm working on an out-of-tree target and am having some problems with rematerialization and spilling. > > The target's load and store instructions affect the condition code register (CCR). Describing this in the InstrInfo.td file using Defs = [CCR] certainly prevents spills and