similar to: [LLVMdev] Schedule MAC instructions

Displaying 20 results from an estimated 4000 matches similar to: "[LLVMdev] Schedule MAC instructions"

2012 Nov 12
1
[LLVMdev] RE : fmac generation for cortex-a9
Hi Renato, You're right it's VMLA/VMLS that are generated. Still don't understand what drives generation for Cortex-A9. I was using fmac for floating point MAC not for fused MAC. Than I realized that we spoke about fma instead of fmac. So back to the original problem why when using -mcpu=cortex-a9 VMLA/VMLS are not generated and when I use -mtriple=armv7-eabi they are ? Best
2012 Nov 09
0
[LLVMdev] fmac generation for cortex-a9
cat /proc/cpuinfo ? Are you sure it's generating VFMA and not VMLA? On Fri, Nov 9, 2012 at 9:35 AM, Sebastien DELDON-GNB < sebastien.deldon at st.com> wrote: > Hi Renato, > > It's definitively not A15. Can this be the case that NEON units for > cortex-A9 support it but isn't documented/recommended ? > And as mentioned before code is working ! > > Seb >
2012 Nov 09
2
[LLVMdev] fmac generation for cortex-a9
Hi Renato, It's definitively not A15. Can this be the case that NEON units for cortex-A9 support it but isn't documented/recommended ? And as mentioned before code is working ! Seb > -----Original Message----- > From: rengolin at gmail.com [mailto:rengolin at gmail.com] On Behalf Of > Renato Golin > Sent: Friday, November 09, 2012 6:27 PM > To: Sebastien DELDON-GNB >
2012 Nov 09
0
[LLVMdev] fmac generation for cortex-a9
Hi Sebastien, ARMv7-M has VFMA and LLVM's "triple" is far from perfect. Wikipedia tells me NovaThor can also be A15, or STE could have cramped a VFPv4 in it? ;) Or possibly, your code never branches into the VFMA. Many things could be happening, but usually, VFMA shouldn't be generated for A9. A GCC bug, maybe? On 9 November 2012 16:51, Sebastien DELDON-GNB
2012 Jun 08
2
[LLVMdev] MC disassembler for ARM
Hi Jim, Thanks for reply. I'm sorry I didn't make myself clear enough. The MCInst created by MCDisassembler depends on the instructions defined in td files. These instructions do not have a one to one mapping to ARM instructions. There are usually one or more instructions defined in the td file correspond to one actual ARM instruction. Thanks, David On Thu, Jun 7, 2012 at 1:27 PM, Jim
2012 Jun 08
0
[LLVMdev] MC disassembler for ARM
That depends on how you define "one ARM instruction." It's not a clear cut thing. For example, is "add r1, r2, r3" the same ARM instruction as "add r1, r2, #4"? What is a distinct instruction and what's a variant encoding of the same instruction is often entirely a matter of convenience. -Jim On Jun 8, 2012, at 6:40 AM, Fan Dawei <fandawei.s at
2012 Nov 09
2
[LLVMdev] fmac generation for cortex-a9
Hi Bastien, Weird gcc is generating fma for my platform STEricsson Novathor with Linaro, code works. It also works when I use LLVM to generate fma (using llc -mtriple=armv7-eabi). Maybe someone from ARM can answer the question ? Seb From: JF Bastien [mailto:jfb at google.com] Sent: Friday, November 09, 2012 5:36 PM To: Sebastien DELDON-GNB Cc: Anitha Boyapati; llvmdev at cs.uiuc.edu Subject:
2012 Jun 07
2
[LLVMdev] MC disassembler for ARM
Hi Tim, Thanks a lot for your help! I'm very grateful. libc.so is a prelinked library, I'll build a non-prelinked one and have another try. I'm now at the start of a binary translation project. I want to convert ARM binary code [*] to llvm ir, which is then translated to binary for our mips like architecture. That's why I'm looking for a decoder for ARM binary. The
2012 Jun 07
0
[LLVMdev] MC disassembler for ARM
On Jun 7, 2012, at 7:53 AM, Fan Dawei <fandawei.s at gmail.com> wrote: > Hi Tim, > > Thanks a lot for your help! I'm very grateful. > > libc.so is a prelinked library, I'll build a non-prelinked one and have another try. > > I'm now at the start of a binary translation project. I want to convert ARM binary code [*] to llvm ir, which is then translated to
2012 Nov 09
0
[LLVMdev] fmac generation for cortex-a9
AFAIK A9 doesn't have VFPv4 or AdvSIMDv2, so it doesn't have VFMA. I don't know what LLVM does, but it shouldn't emit VFMA when you target A9. VMLA isn't a fused multiply-add, it's a multiply followed by an add and has different latency as well as precision. On Thu, Nov 8, 2012 at 4:57 AM, Sebastien DELDON-GNB < sebastien.deldon at st.com> wrote: > Hi Anitha,
2012 Nov 08
2
[LLVMdev] fmac generation for cortex-a9
Hi Anitha, Thanks for your answer but -mcpu=cortex-a9 -mattr=+vfp4 doesn' t enable fused mac generation for me. I would like just to understand why -mtriple=armv7-eabi enables it while -mcpu=cortex-a9 seems to disable it ? Seb > -----Original Message----- > From: Anitha Boyapati [mailto:anitha.boyapati at gmail.com] > Sent: Thursday, November 08, 2012 10:22 AM > To: Sebastien
2012 Jun 06
2
[LLVMdev] MC disassembler for ARM
Hi, I'm considering to use MC disassembler for ARM target in a binary translation project. However after trying some ARM binary and I find that there are a lot of instructions that the disassembler fails to to decoding. Could anyone give me some information about the maturity of ARM disassembler? Thanks! David -------------- next part -------------- An HTML attachment was scrubbed... URL:
2012 Jun 06
0
[LLVMdev] MC disassembler for ARM
On Jun 5, 2012, at 7:44 PM, Fan Dawei <fandawei.s at gmail.com> wrote: > Hi, > > I'm considering to use MC disassembler for ARM target in a binary translation project. However after trying some ARM binary and I find that there are a lot of instructions that the disassembler fails to to decoding. > > Could anyone give me some information about the maturity of ARM
2012 Jun 07
0
[LLVMdev] MC disassembler for ARM
Hi David, On Thu, Jun 7, 2012 at 10:17 AM, Fan Dawei <fandawei.s at gmail.com> wrote: > Could you please tell me more about $a, $t and $d symbols? How these symbols > are used to define different regions? Where I can find this symbols in ELF > object file? At the start of each range of ARM code, an assembler or compiler should produce a "$a" symbol with that address, and
2012 Apr 25
1
[LLVMdev] LLVM Backend for Z80. ADD -> replaced -> OR
Hello. I have played with DataLayout and found a solution with is uknown to me. I added S16 and also s0:16:16, but it had not worked. Then I found that in Z80FrameLowering.h I am calling TargetFrameLowering with stack aligment set to 8. So I changed it to 2 bytes. But this also didn't help. Then I changed llc to show TargetDataLayout and found that a option is set to a0:0:64. So I changed
2012 Jun 07
2
[LLVMdev] MC disassembler for ARM
Hi Tim, Thanks a lot for the reply. I tested libc.so which is a shared library. llvm-objdump also report some disassemble errors. Could you please tell me more about $a, $t and $d symbols? How these symbols are used to define different regions? Where I can find this symbols in ELF object file? Thanks, David I'm now try to find a decoder of ARM instructions in oder On Thu, Jun 7, 2012
2011 Oct 19
1
[LLVMdev] Error when cond of select instruction is a vector
Hi Rotem, What do you mean by "you can use the <4 x float> type for which the vselect works". Do you mean that then back-end can correctly split the operands when it is a four elements vector? I've try that, but it still fails. On Wed, Oct 19, 2011 at 4:21 PM, Rotem, Nadav <nadav.rotem at intel.com> wrote: > This is indeed a bug. I get a different error on my
2013 Dec 20
0
[LLVMdev] Commutability of X86 FMA3 instructions.
Hi Lang, Unfortunately, I don't have an answer on the commutability question, but I wanted to let you know that I filed a bug on this: http://llvm.org/bugs/show_bug.cgi?id=17229 This also shows a memory operand variant of the fma that you may want to consider in your patch and testcases. Thanks! On Thu, Dec 19, 2013 at 10:45 PM, Lang Hames <lhames at gmail.com> wrote: > Hi all,
2013 Dec 20
2
[LLVMdev] Commutability of X86 FMA3 instructions.
Hi all, The 213 variant of the FMA3 instructions is currently marked commutable (see X86InstrFMA.td). Is that safe? According to the ISA the FMA3 instructions aren't commutable for non-numeric results, so I'd have thought commuting this would only be valid in fast-math mode? For the curious, the reason that I'm asking is that we currently always select the 213 variant, but this
2011 Nov 03
1
[LLVMdev] Why there is no unary operator in LLVM?
Hi llvmdev, I've noticed that there is no unary operator in LLVM. For unary operator such as Neg or Or operator, the IR builder just creates a binary operation with one dummy operand, 01823 <http://llvm.org/doxygen/classllvm_1_1BinaryOperator.html#a073c092ce74a122e898e435e60e84599> BinaryOperator <http://llvm.org/doxygen/classllvm_1_1BinaryOperator.html>