https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68664
Aldy Hernandez <aldyh at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |aldyh at gcc dot gnu.org
--- Comment #7 from Aldy Hernandez <aldyh at gcc dot gnu.org> ---
On both aarch64 and ppc64, this starts happening after scheduling changes:
commit 08993ad1c669cab64baf352f79cd7f8584dd8e0c
Author: jgreenhalgh <jgreenhalgh@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu Oct 1 09:33:40 2015 +0000
[Patch 2/2 ARM/AArch64] Add a new Cortex-A53 scheduling model
* config/arm/aarch-common-protos.h
(aarch_accumulator_forwarding): New.
(aarch_forward_to_shift_is_not_shifted_reg): Likewise.
* config/arm/aarch-common.c (aarch_accumulator_forwarding): New.
(aarch_forward_to_shift_is_not_shifted_reg): Liekwise.
* config/arm/cortex-a53.md: Rewrite.
and
commit 5379d8d457b300219d3d8eda38caaa9916f98078
Author: dje <dje@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon Jan 19 18:33:24 2015 +0000
* config/rs6000/default64.h: Include rs6000-cpus.def.
(TARGET_DEFAULT) [LITTLE_ENDIAN]: Use ISA 2.7 (POWER8).
(TARGET_DEFAULT) [BIG_ENDIAN]: Use POWER4.
* config/rs6000/driver-rs6000.c (detect_processor_aix): Add POWER7
and POWER8.
* config/rs6000/linux64.h (PROCESSOR_DEFAULT64): Always default to
POWER8.
* config/rs6000/rs6000.c (rs6000_file_start): Emit .machine
pseudo-op to specify assembler dialect.
There is further analysis by James on bz#77468.
On arm-eabi -mhard-float I was not able to reproduce, so perhaps we could
remove the arm-*-* target, and just leave aarch64.
Note, the speculative execution of sqrt on both aarch64 and ppc64 happens in
the sched1 rtl pass.
