On 18/09/17 17:39, Richard Sandiford wrote:
> ALL_REGS doesn't function as a union class of POINTER_REGS and FP_REGS
> since it includes the CC register as well. REGNO_REG_CLASS (CC_REGNUM)
> is NO_REGS, but of course NO_REGS rightly doesn't include CC_REGNUM.
>
> Adding a union class for POINTER+FP allows the RA to use it as the
> preferred or alternative class of a pseudo. It also works as a
> union class of GENERAL+FP for modes that aren't allowed in SP.
>
> This is also needed for the SVE port, which adds predicate registers
> to the mix.
>
> The combination of r252033 and this patch fixes PR71307. Tested on
> aarch64-linux-gnu. Also tested on SPEC2k6, where there were no
> differences outside the (mostly low) noise. OK to install?
>
> The main potential disadvantage I can see is that the -fsched-pressure
> code isn't very good at handling union classes: it generally just updates
> one pressure class for each pseudo. I haven't found any specific examples
> of that causing problems though.
>
> Thanks,
> Richard
>
>
> 2017-09-15 Richard Sandiford <[email protected]>
> Alan Hayward <[email protected]>
> David Sherwood <[email protected]>
>
> gcc/
> PR target/71307
> * config/aarch64/aarch64.h (POINTER_AND_FP_REGS): New reg class.
> (REG_CLASS_NAMES, REG_CLASS_CONTENTS): Update accordingly.
> * config/aarch64/aarch64.c (aarch64_class_max_nregs): Handle
> POINTER_AND_FP_REGS.
>
> gcc/testsuite/
> PR target/71307
> * gcc.target/aarch64/vect_copy_lane_1.c: Remove XFAIL.
OK.
R.
>
> Index: gcc/config/aarch64/aarch64.h
> ===================================================================
> --- gcc/config/aarch64/aarch64.h 2017-09-15 14:47:33.167333414 +0100
> +++ gcc/config/aarch64/aarch64.h 2017-09-18 17:31:34.720209011 +0100
> @@ -452,6 +452,7 @@ enum reg_class
> POINTER_REGS,
> FP_LO_REGS,
> FP_REGS,
> + POINTER_AND_FP_REGS,
> ALL_REGS,
> LIM_REG_CLASSES /* Last */
> };
> @@ -467,6 +468,7 @@ #define REG_CLASS_NAMES \
> "POINTER_REGS", \
> "FP_LO_REGS", \
> "FP_REGS", \
> + "POINTER_AND_FP_REGS", \
> "ALL_REGS" \
> }
>
> @@ -479,6 +481,7 @@ #define REG_CLASS_CONTENTS
> \
> { 0xffffffff, 0x00000000, 0x00000003 }, /* POINTER_REGS */ \
> { 0x00000000, 0x0000ffff, 0x00000000 }, /* FP_LO_REGS */ \
> { 0x00000000, 0xffffffff, 0x00000000 }, /* FP_REGS */
> \
> + { 0xffffffff, 0xffffffff, 0x00000003 }, /* POINTER_AND_FP_REGS */\
> { 0xffffffff, 0xffffffff, 0x00000007 } /* ALL_REGS */ \
> }
>
> Index: gcc/config/aarch64/aarch64.c
> ===================================================================
> --- gcc/config/aarch64/aarch64.c 2017-09-18 14:58:24.012256423 +0100
> +++ gcc/config/aarch64/aarch64.c 2017-09-18 17:31:34.720209011 +0100
> @@ -6009,6 +6009,7 @@ aarch64_class_max_nregs (reg_class_t reg
> case POINTER_REGS:
> case GENERAL_REGS:
> case ALL_REGS:
> + case POINTER_AND_FP_REGS:
> case FP_REGS:
> case FP_LO_REGS:
> return
> Index: gcc/testsuite/gcc.target/aarch64/vect_copy_lane_1.c
> ===================================================================
> --- gcc/testsuite/gcc.target/aarch64/vect_copy_lane_1.c 2016-11-22
> 21:16:00.000000000 +0000
> +++ gcc/testsuite/gcc.target/aarch64/vect_copy_lane_1.c 2017-09-18
> 17:31:34.720209011 +0100
> @@ -45,8 +45,7 @@ BUILD_TEST (uint32x2_t, uint32x4_t, ,
> BUILD_TEST (float64x1_t, float64x2_t, , q, f64, 0, 1)
> BUILD_TEST (int64x1_t, int64x2_t, , q, s64, 0, 1)
> BUILD_TEST (uint64x1_t, uint64x2_t, , q, u64, 0, 1)
> -/* XFAIL due to PR 71307. */
> -/* { dg-final { scan-assembler-times "dup\\td0, v1.d\\\[1\\\]" 3 { xfail
> *-*-* } } } */
> +/* { dg-final { scan-assembler-times "dup\\td0, v1.d\\\[1\\\]" 3 } } */
>
> /* vcopyq_lane. */
> BUILD_TEST (poly8x16_t, poly8x8_t, q, , p8, 15, 7)
>
