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| author | Andre Vieira <andre.simoesdiasvieira@arm.com> | 2023-02-02 10:01:13 +0000 |
|---|---|---|
| committer | Andre Vieira <andre.simoesdiasvieira@arm.com> | 2023-02-02 10:01:13 +0000 |
| commit | d45ec8a732f449647afa89e46b80a4e0614ec28d (patch) | |
| tree | 24b143aded8b691c315f63eb0cf5cf9d7b63e551 /gcc/config/arm/arm.cc | |
| parent | 75b58e77706e8b5057770f040005950940a9a0f5 (diff) | |
| download | gcc-d45ec8a732f449647afa89e46b80a4e0614ec28d.zip gcc-d45ec8a732f449647afa89e46b80a4e0614ec28d.tar.gz gcc-d45ec8a732f449647afa89e46b80a4e0614ec28d.tar.bz2 | |
arm: Remove unnecessary zero-extending of MVE predicates before use [PR 107674]
This patch teaches GCC that zero-extending a MVE predicate from 16-bits to
32-bits and then only using 16-bits is a no-op.
It does so in two steps:
- it lets gcc know that it can access any MVE predicate mode using any other MVE
predicate mode without needing to copy it, using the TARGET_MODES_TIEABLE_P hook,
- it teaches simplify_subreg to optimize a subreg with a vector outermode, by
replacing this outermode with a same-sized integer mode and trying the
avalailable optimizations, then if successful it surrounds the result with a
subreg casting it back to the original vector outermode.
gcc/ChangeLog:
PR target/107674
* config/arm/arm.cc (arm_hard_regno_mode_ok): Use new MACRO.
(arm_modes_tieable_p): Make MVE predicate modes tieable.
* config/arm/arm.h (VALID_MVE_PRED_MODE): New define.
* simplify-rtx.cc (simplify_context::simplify_subreg): Teach
simplify_subreg to simplify subregs where the outermode is not scalar.
gcc/testsuite/ChangeLog:
* gcc.target/arm/mve/mve_vpt.c: Change to remove unecessary zero-extend.
Diffstat (limited to 'gcc/config/arm/arm.cc')
| -rw-r--r-- | gcc/config/arm/arm.cc | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/gcc/config/arm/arm.cc b/gcc/config/arm/arm.cc index efc4834..4d9d202 100644 --- a/gcc/config/arm/arm.cc +++ b/gcc/config/arm/arm.cc @@ -25656,10 +25656,7 @@ arm_hard_regno_mode_ok (unsigned int regno, machine_mode mode) return false; if (IS_VPR_REGNUM (regno)) - return mode == HImode - || mode == V16BImode - || mode == V8BImode - || mode == V4BImode; + return VALID_MVE_PRED_MODE (mode); if (TARGET_THUMB1) /* For the Thumb we only allow values bigger than SImode in @@ -25738,6 +25735,10 @@ arm_modes_tieable_p (machine_mode mode1, machine_mode mode2) if (GET_MODE_CLASS (mode1) == GET_MODE_CLASS (mode2)) return true; + if (TARGET_HAVE_MVE + && (VALID_MVE_PRED_MODE (mode1) && VALID_MVE_PRED_MODE (mode2))) + return true; + /* We specifically want to allow elements of "structure" modes to be tieable to the structure. This more general condition allows other rarer situations too. */ |