Displaying 20 results from an estimated 1000 matches similar to: "{ARM} IfConversion does not detect BX instruction as a branch"
2017 Oct 11
2
{ARM} IfConversion does not detect BX instruction as a branch
On Tue, Oct 10, 2017 at 4:48 PM, Friedman, Eli via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> On 10/9/2017 3:10 AM, Gaël Jobin via llvm-dev wrote:
>
> Hi all,
>
> I got a silly bug when compiling our project with the latest Clang. Here's
> the outputted assembly:
>
> tst r3, #255
> strbeq r6, [r7]
> ldreq r6, [r4, r6, lsl #2]
> strne r6, [r7, #4]
2018 Apr 09
2
How to get the case value from Machine Instruction
Hi, guys
I am interesting about how to get the switch case value form the Machine Instruction.
I know the switch will be converted to jump-table in the Machine Instruction.
And in the phase CodeGen , the case-value of SwitchInst can get esasly.
but it seems no case -value in Machine Instruction.
The MI as follows:
Frame Objects:
fi#0: size=1, align=0, at location [SP]
fi#1: size=4,
2018 Apr 09
0
How to get the case value from Machine Instruction
Some glitch in the emailer? I have received this message 3 times in a row!?
I think that by the time it gets as far as MI-level there is no reversible
method of determining the 'case' label at all. The reason I say this, is
that I have often seen optimisations that coalesce groups of values into
interesting logical tests and jump-tables are completely avoided. For
example, a simple
2018 Apr 10
1
How to get the case value from Machine Instruction
Thanks for your help.
Is there possible I can get the realily case value form the MI?
For the case in https://bugs.llvm.org/show_bug.cgi?id=34902.
as follows.
#############################
* GCC v7.1 generated assembly
#############################
** Options: -Os -marm -march=armv7-a
foo:
@ args = 0, pretend = 0, frame = 0
@ frame_needed = 0, uses_anonymous_args = 0
sub
2018 Apr 09
0
How to get the case value from Machine Instruction
Hi, guys
I am interesting about how to get the switch case value form the Machine Instruction.
I know the switch will be converted to jump-table in the Machine Instruction.
And in the phase CodeGen , the case-value of SwitchInst can get esasly.
but it seems no case -value in Machine Instruction.
The MI as follows:
Frame Objects:
fi#0: size=1, align=0, at location [SP]
fi#1: size=4,
2007 Sep 07
1
[LLVMdev] Call instruction
My home e--mail is down, which is where I get my llvm feeds, so please copy
any replies to this address as well as the list.
The call instruction can define implicit defs. What are the semantics when
the call includes a use with a kill of some register and also an implicit def
of that register? Is the register to be considered live out at that point?
I've found a failing testcase where
2018 Jun 15
2
Strange Machineinstr
Hi
I write a machinefunction pass to print all the machinefunction's machine
instructions.
My target architecture is ARM. However, I don't understand some part of the
machine instructions.
Below is some of the assembly language for function A.
.text:0001C034 STMFD SP!, {R4,R10,R11,LR}
> .text:0001C038 ADD R11, SP, #8
> .text:0001C03C
2018 Jun 15
3
Strange Machineinstr
Hi Krzysztof
Thank you very much for your quick and clear reply. I know that MIR may not
match hardware instructions directly. However, I think the semantics should
be similar.
For example, the first instruction is a store-multiple instruction in ARM.
I think the first four MIR I shown should have the similar semantics with
the first three hardware instructions. I still cannot see the
2012 Feb 04
4
[LLVMdev] ARMLoadStoreOptimizer bug
Evan & llvmdev,
I'm seeing a case where ARM Load/Store optimizer is breaking code. I have
not had any luck trying to come up with a minimal example; it is breaking
in our stage 2 LLVM build.
But here's what I'm seeing in the debug output:
# Before ARMLoadStoreOptimizer:
BB#21: derived from LLVM BB %cond.end
Live Ins: %LR %R0 %R1 %R7 %R10 %R11
Predecessors according to
2012 Feb 07
0
[LLVMdev] ARMLoadStoreOptimizer bug
I've committed a fix: r149970. Please try it. I would really appreciate it if you can provide us with a test case (unreduced test case is fine).
Evan
On 2012 2 4, at 09:46, David Meyer <pdox at google.com> wrote:
> Evan & llvmdev,
>
> I'm seeing a case where ARM Load/Store optimizer is breaking code. I have not had any luck trying to come up with a minimal example;
2013 Feb 08
2
[LLVMdev] help with X86 DAG->DAG Instruction Selection
I have an llvm ir, which generates the following machine code using llc
(llvm 3.0 on win32) after # *** IR Dump After X86 DAG->DAG Instruction
Selection ***:
The first three lines and the last two lines alone together are used to
compute "sin" for some double number.
- line 1: move the stack pointer down 8
- line 2: copy the updated stack pointer to a base register
- line 3: copy a
2013 Feb 08
0
[LLVMdev] help with X86 DAG->DAG Instruction Selection
Hi Peng,
Can you please open a bugzilla and attache the LL file ? Can you please reproduce it on ToT ?
Thanks,
Nadav
On Feb 7, 2013, at 9:08 PM, Peng Cheng <gm4cheng at gmail.com> wrote:
> I have an llvm ir, which generates the following machine code using llc (llvm 3.0 on win32) after # *** IR Dump After X86 DAG->DAG Instruction Selection ***:
>
> The first three lines
2013 May 13
1
[LLVMdev] Problem with MachineFunctionPass and JMP
Hi !
I'm trying to modify the code in a machine function pass…
I added a new basicblock and I want to add a jump to an another BB from my new BB.
Here is my code :
bool Obfuscation::runOnMachineFunction(MachineFunction &MF) {
MachineBasicBlock *newEntry = MF.CreateMachineBasicBlock();
MF.insert(MF.begin(), newEntry);
std::vector<MachineBasicBlock*> origBB;
2018 Dec 04
2
Incorrect placement of an instruction after PostRAScheduler pass
Hi,
I’m facing a crash issue (--target=arm-linux-gnueabi
-march=armv8-a+crc -mfloat-abi=hard) and debugging the problem, I
found that an intended branch was not taken due to bad code generation
after the Post RA Scheduler pass. A CMPri instruction after an
INLINEASM block (which inturn contains a cmp, bne instruction) is
being moved before the INLINEASM block incorrectly resulting in two
2013 Aug 02
0
[LLVMdev] Missing optimization - constant parameter
> I expected that this optimization would be picked
> up in a cse, gvn, machine-cse or even peepholing pass.
>
> Comments?
At the LLVM IR level this is represented as
define i64 @caller() #0 {
entry:
store i64* @val, i64** @p, align 8, !tbaa !0
store i64 12345123400, i64* @val, align 8, !tbaa !3
%call = tail call i64 @xtr(i64 12345123400) #2
ret i64 %call
}
Which is
2013 Aug 02
2
[LLVMdev] Missing optimization - constant parameter
On Aug 2, 2013, at 1:37 PM, Rafael Espíndola <rafael.espindola at gmail.com> wrote:
>> I expected that this optimization would be picked
>> up in a cse, gvn, machine-cse or even peepholing pass.
>>
>> Comments?
>
>
> At the LLVM IR level this is represented as
>
> define i64 @caller() #0 {
> entry:
> store i64* @val, i64** @p, align 8, !tbaa
2007 Dec 20
1
[LLVMdev] Code Generation Problem llvm 1.9
I sent a long message yesterday describing a problem I thought had to do with the JIT stubs.
After further investigating, the problem seems to be in the code generation.
The following basic block seems to have an error in it's code generation:
__exp.exit: ; preds = %codeRepl258, %__exp_bb_bb.exit
phi double [ 1.000000e+00, %codeRepl258 ], [ %.reload.reload.i,
2013 Jul 23
2
[LLVMdev] Question on optimizeThumb2JumpTables
In looking at the code in
ARMConstantislandPass.cpp::optimizeThumb2JumpTables(), I see that there is
the following condition for not creating tbb-based jump tables:
// The instruction should be a tLEApcrel or t2LEApcrelJT; we want
// to delete it as well.
MachineInstr *LeaMI = PrevI;
if ((LeaMI->getOpcode() != ARM::tLEApcrelJT &&
2012 Sep 18
2
[LLVMdev] liveness assertion problem in llc
Hi,
I am working on a backend for a CGRA architecture with advanced predicate support (as on EPIC machines and as first used in the OpenIMPACT compiler). Until last month, the backend was working fine, but since the r161643 commit by stoklund, my backend doesn't work anymore. I think I noticed some related commits later on, and the assertion I get on the latest trunk (r164162) differs from
2013 Jul 29
0
[LLVMdev] Question on optimizeThumb2JumpTables
Hi Jakob,
You're the unfortunate soul who last touched the constant island pass,
right? Do you happen to have any insight for Daniel?
Chad
On Tue, Jul 23, 2013 at 9:55 AM, Daniel Stewart <stewartd at codeaurora.org>wrote:
> In looking at the code in
> ARMConstantislandPass.cpp::optimizeThumb2JumpTables(), I see that there is
> the following condition for not creating