search for: sub_ss

All, I've been trying to simplify the way LLVM models sub-register relationships a bit, and the X86 sub_ss and sub_sd sub-register indices are getting in the way. I want to get rid of them. These sub-registers are special, they are only mentioned here: let CompositeIndices = [(sub_ss), (sub_sd)] in { def XMM0: Register<"xmm0">, DwarfRegNum<[17, 21, 21]>; def XMM1: Register&...

Jakob Stoklund Olesen <jolesen at apple.com> writes: > These sub-registers are special, they are only mentioned here: > > let CompositeIndices = [(sub_ss), (sub_sd)] in { > def XMM0: Register<"xmm0">, DwarfRegNum<[17, 21, 21]>; > def XMM1: Register<"xmm1">, DwarfRegNum<[18, 22, 22]>; > ... I'm confused. Below you note that they are used in patterns, so they are certainly mentioned more...

Jakob Stoklund Olesen <jolesen at apple.com> writes: >> If the 128-bit register is not ever used as a 128-bit register, >> shouldn't the coalescer pick the 64- or 32-bit register? > > That optimization is not currently implemented for sub-registers. For > example, if you create a GR64 virtual register and only ever use the > sub_32bit sub-register, it would be

Jakob Stoklund Olesen <jolesen at apple.com> writes: >> What happens if the result of the above pattern using COPY_TO_REGCLASS >> is spilled? Will we get a 64-bit store or a 128-bit store? > > This behavior isn't affected by the change. FR64 registers are spilled > with 64-bit stores, and VR128 registers are spilled with 128-bit > stores. > > When the

On Jul 26, 2012, at 9:43 AM, dag at cray.com wrote: > Jakob Stoklund Olesen <jolesen at apple.com> writes: > >> As far as I can tell, all sub-register operations involving sub_ss and >> sub_sd can simply be replaced with COPY_TO_REGCLASS: >> >> def : Pat<(v4i32 (X86Movsd VR128:$src1, VR128:$src2)), >> (VMOVSDrr VR128:$src1, (EXTRACT_SUBREG (v4i32 VR128:$src2), >> sub_sd))>; &g...

On Jul 26, 2012, at 10:28 AM, dag at cray.com wrote: > Jakob Stoklund Olesen <jolesen at apple.com> writes: > >>> What happens if the result of the above pattern using COPY_TO_REGCLASS >>> is spilled? Will we get a 64-bit store or a 128-bit store? >> >> This behavior isn't affected by the change. FR64 registers are spilled >> with 64-bit

Hey guys, Are spills/reloads of AVX registers using aligned stores/loads? I can't seem to find the code that aligns the stack slots to 32-bytes. Could someone point me in the right direction? Thanks, Cameron -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20110825/b5724dec/attachment.html>

...tes. Could > someone point me in the right direction? The register class has 256-bit spill alignment: def VR256 : RegisterClass<"X86", [v32i8, v16i16, v8i32, v4i64, v8f32, v4f64], 256, (sequence "YMM%u", 0, 15)> { let SubRegClasses = [(FR32 sub_ss), (FR64 sub_sd), (VR128 sub_xmm)]; } /jakob

Does anyone know exactly what ComposerIndices in Target.td is all about? I see just one place where it's used in X86 but it's not clear from the comments in Target.td and it's one usage, exactly what this feature is about. Tia. Reed

...int me in the right direction? > > The register class has 256-bit spill alignment: > > def VR256 : RegisterClass<"X86", [v32i8, v16i16, v8i32, v4i64, v8f32, v4f64], > 256, (sequence "YMM%u", 0, 15)> { > let SubRegClasses = [(FR32 sub_ss), (FR64 sub_sd), (VR128 sub_xmm)]; > } > > /jakob > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20110901/3403477c/attachment.html>

On Jun 15, 2010, at 2:48 PM, Jakob Stoklund Olesen wrote: > I am considering adding a new target independent codegen-only COPY instruction to our MachineInstr representation. It would be used to replace INSERT_SUBREG, EXTRACT_SUBREG, and virtual register copies after instruction selection. Selection DAG still needs {INSERT,EXTRACT}_SUBREG, but they would not appear as MachineInstrs any longer.

I am considering adding a new target independent codegen-only COPY instruction to our MachineInstr representation. It would be used to replace INSERT_SUBREG, EXTRACT_SUBREG, and virtual register copies after instruction selection. Selection DAG still needs {INSERT,EXTRACT}_SUBREG, but they would not appear as MachineInstrs any longer. The COPY instruction handles subreg operations with less