similar to: [LLVMdev] Question on optimizeThumb2JumpTables

Displaying 20 results from an estimated 800 matches similar to: "[LLVMdev] Question on optimizeThumb2JumpTables"

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
2013 Jul 29
1
[LLVMdev] Question on optimizeThumb2JumpTables
On Jul 29, 2013, at 6:50 AM, Chad Rosier <chad.rosier at gmail.com> wrote: > Hi Jakob, > You're the unfortunate soul who last touched the constant island pass, right? Do you happen to have any insight for Daniel? Sorry, no. I don't remember working with that particular bit of code. You could try digging through the commit logs. Thanks, /jakob > On Tue, Jul 23, 2013 at
2018 Mar 08
2
Relationship between MachineMemOperand and X86II::getMemoryOperandNo
Hello, I'm trying to understand the relationship between MachineMemOperand and, on X86, memory operands of machine instructions. The latter seem to be operands held in order by the MachineInstr, from an offset onwards - Base, Scale, Index, Displacement, Segment. The former, if I understand it correctly, is used to hold a relationship back to IR load/store instructions. Is it possible to have
2018 Mar 08
0
Relationship between MachineMemOperand and X86II::getMemoryOperandNo
Hello Mircea, > On 8 Mar 2018, at 18:52, Mircea Trofin via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hello, > > I'm trying to understand the relationship between MachineMemOperand and, on X86, memory operands of machine instructions. The latter seem to be operands held in order by the MachineInstr, from an offset onwards - Base, Scale, Index, Displacement,
2018 Mar 09
1
Relationship between MachineMemOperand and X86II::getMemoryOperandNo
Thanks for the details! How should we think of the case where an instruction has memory operands (in the sense that X86II::getMemoryOperandNo >=0), but doesn't have MachineMemOperands? I'm seeing an example in the case of __builtin_prefetch (lowered via SelectionDAG::getMemIntrinsicNode, which produces a MachineMemOperand) vs __builtin_ia32_gatherpfdpd, lowered through getPrefetchNode
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
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 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,
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;
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
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
2013 Aug 02
2
[LLVMdev] Missing optimization - constant parameter
For the little C test program where a constant is stored in memory and also used as a parameter: #include <stdint.h> uint64_t val, *p; extern uint64_t xtr( uint64_t); uint64_t caller() { uint64_t x; p = &val; x = 12345123400L; *p = x; return xtr(x); } clang (3.2, 3.3 and svn) generates the following X86 code (at -O3): caller: movq
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
2017 Oct 09
4
{ARM} IfConversion does not detect BX instruction as a branch
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] > ldr r6, [r4, r6, lsl #2] > bx r6 For the code to execute correctly, either the _ldr_ should be a _ldrne_ instruction or the _ldreq_ instruction should be removed. The error seems to
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
2012 Sep 18
0
[LLVMdev] liveness assertion problem in llc
On Sep 18, 2012, at 1:45 PM, Bjorn De Sutter <bjorn.desutter at elis.ugent.be> wrote: > 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
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
2013 Aug 02
2
[LLVMdev] Missing optimization - constant parameter
On Aug 2, 2013, at 1:37 PM, Rafael EspĂ­ndola <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
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