similar to: [LLVMdev] Question about arm thumb2 code generation

On Jul 27, 2012, at 9:04 AM, Sebastien DELDON-GNB <sebastien.deldon at st.com> wrote: > Hi all, > > Does llc –march=thumb –mcpu=cortex-a9 enable generation of thumb2 code for armv7 ? That's how I usually do it. Somewhere in the target description we associate a9 with -mattr=+thumb2. There are plenty of other ways to get the same result, and it's all very confusing and

Thanks andrew for the answer. I would like to generate code for Cortex-A9 that don't use neon for fp computation but vfpv3 -d16. I've tried some combination of -mattr=+neon,-neonfp,+vfp3,+d16 but couldn't get ".fpu vfpv3-d16" directive generated in assembly file. Do you know how to make it happen ? Best Regards Seb From: Andrew Trick [mailto:atrick at apple.com] Sent:

Hi Rotem, Thanks for the quick answer, how do I know which type is legal/illegal with respect to calling convention ? Best Regards Seb > -----Original Message----- > From: Rotem, Nadav [mailto:nadav.rotem at intel.com] > Sent: Thursday, July 05, 2012 11:21 AM > To: Sebastien DELDON-GNB; llvmdev at cs.uiuc.edu > Subject: RE: Vector argument passing abi for ARM ? > > The

Hi Duncan, I also thought it was a bug, especially since it worked with LLVM 3.0, but since it is not defined by ABI, I was not sure if I need to submit it as a BUG. I wanted to be sure that it is an actual BUG before submitting it and got the not-a-bug answer. Here is a small example to reproduce the problem I'm experiencing: ; ModuleID = 'bugparam.ll' target datalayout =

Hi Sebastien, > I also thought it was a bug, especially since it worked with LLVM 3.0, but since it is not defined by ABI, I was not sure if I need to submit it as a BUG. yes it is a bug. > I wanted to be sure that it is an actual BUG before submitting it and got the not-a-bug answer. I didn't read Nadav's reply as saying there was no bug, in fact he explicitly said in his email

Hi Sebastien, > Thanks for the quick answer, how do I know which type is legal/illegal with respect to calling convention ? the code generators are supposed to produce working code no matter what the parameter type is. The fact that the ARM ABI doesn't specify how <2 x i8> is passed just means that the code generators can pass it using whatever technique it feels like (since it

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

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:

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 >

Hello, I'm trying to convince llc to compile into thumb2 ISA on ARMv7. I'm using: -march=thumb -mattr=v7,thumb2,vfp3 but llc complains about this with: llc: error: invalid target 'thumb -mattr=v7,thumb2,vfp3' I'm using LLVM from Aug 29 2011. To me the set of options looks sane so I'd like to ask what's wrong with this. Thanks! Karel

Hi Eli, Thanks for the answer, it clarifies the situation for me. Do you know if there is Pass in LLVM that could be adapted to 'legalize' intrinsics calls ? Or shall I define my own intrinsics for non supported types ? Best Regards Seb ________________________________________ De : Eli Friedman [eli.friedman at gmail.com] Date d'envoi : vendredi 21 septembre 2012 11:54 À : Sebastien

Hi all, I would like to know if LLVM Neon intrinsics are designed to support only 'Legal' types for NEON units. Using llc -march=arm -mcpu=cortex-a9 vmax4.ll -o vmax4.s on following ll code: ; ModuleID = 'vmax.ll' target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n32" target triple =

Hi James, Thanks for the answer, for Cortex-A9 would you recommend to generate thumb2 code or ARM code ? What would be the best performance wise ? Best Regards Seb > -----Original Message----- > From: James Molloy [mailto:james.molloy at arm.com] > Sent: Thursday, May 31, 2012 9:57 AM > To: Sebastien DELDON-GNB > Cc: llvmdev at cs.uiuc.edu > Subject: Re: [LLVMdev] llc support

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 >

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

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,

Hi James, Thanks for the answer, can you elaborate on difference between thumb, thumb2, ARM, thumbv7. I'm a bit lost right now. When specifying thumbv7 llc will generate thumb only code, not thumb2 ? Best Regards Seb > -----Original Message----- > From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] > On Behalf Of James Molloy > Sent: Tuesday, May 29,

On 12 February 2013 16:56, Sebastien DELDON-GNB <sebastien.deldon at st.com>wrote: > If this helps taking your decision, there are at least two benchmarks for > which disabling vmlx-forwarding makes a significant difference. > I think Evan's worry was to base this decision on visible and comprehensible benchmarks, such as the test-suite. If I get lucky I may be able to run

Hi all, I've a .ll code that use double precision fmul/fadd or fmul/fsub. When I compile it using llc -mcpu=cortex-a9 I couldn't get vmla/vmls generated even using -fp-contract=fast, but when I use option -mtriple=armv7-eabi instead of -mcpu=cortex-a9 fused mac are generated. Can someone explain me why ? Thanks for your answers Seb -------------- next part -------------- An HTML

On Sep 21, 2012, at 2:58 AM, Sebastien DELDON-GNB <sebastien.deldon at st.com> wrote: > Hi Eli, > > Thanks for the answer, it clarifies the situation for me. Do you know if there is Pass in LLVM that could be adapted to 'legalize' intrinsics calls ? > Or shall I define my own intrinsics for non supported types ? You should never generate these sorts of intrinsics with