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Re: [PATCH][GCC][AArch64] Inline calls to lrint when possible
- From: Christophe Lyon <christophe dot lyon at linaro dot org>
- To: Tamar Christina <Tamar dot Christina at arm dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, nd <nd at arm dot com>, Richard Earnshaw <Richard dot Earnshaw at arm dot com>, Marcus Shawcroft <Marcus dot Shawcroft at arm dot com>
- Date: Mon, 12 Jun 2017 14:10:38 +0200
- Subject: Re: [PATCH][GCC][AArch64] Inline calls to lrint when possible
- Authentication-results: sourceware.org; auth=none
- References: <VI1PR0801MB20312637867C59D802147A5CFFC80@VI1PR0801MB2031.eurprd08.prod.outlook.com> <20170608165033.GD29952@arm.com>
Hi Tamar,
On 8 June 2017 at 18:50, James Greenhalgh <james.greenhalgh@arm.com> wrote:
> On Wed, Jun 07, 2017 at 12:38:27PM +0100, Tamar Christina wrote:
>> Hi All,
>>
>> This patch allows the inlining of lrint when -fno-math-errno
>> assuming that errno does not need to be set when the rounded value
>> is not representable as a long.
>>
>> The case
>>
>> void f(double *a, long *b, double x)
>> {
>> *a = __builtin_rint(x);
>> *b = __builtin_lrint(x);
>> }
>>
>> now generates with -fno-math-errno:
>>
>> f:
>> frintx d0, d0
>> fcvtzs x2, d0
>> str d0, [x0]
>> str x2, [x1]
>> ret
>>
>> When the flag is not used the same function call is emitted as before:
>>
>> f:
>> stp x29, x30, [sp, -32]!
>> frintx d1, d0
>> add x29, sp, 0
>> str x19, [sp, 16]
>> mov x19, x1
>> str d1, [x0]
>> bl lrint
>> str x0, [x19]
>> ldr x19, [sp, 16]
>> ldp x29, x30, [sp], 32
>> ret
>>
>> Bootstrapped and regtested on aarch64-none-linux-gnu and no regressions.
>> The patch also has no regressions on Spec2006.
>>
>> Ok for trunk?
>
> OK.
>
> Thanks,
> James
>
>>
>> gcc/
>> 2017-06-07 Tamar Christina <tamar.christina@arm.com>
>>
>> * config/aarch64/aarch64.md (lrint<GPF:mode><GPI:mode>2): New.
>>
>> gcc/testsuite/
>> 2017-06-07 Tamar Christina <tamar.christina@arm.com>
>>
>> * gcc.target/aarch64/lrint-matherr.h: New.
>> * gcc.target/aarch64/inline-lrint_1.c: New.
>> * gcc.target/aarch64/inline-lrint_2.c: New.
>> * gcc.target/aarch64/no-inline-lrint_1.c: New.
>> * gcc.target/aarch64/no-inline-lrint_2.c: New.
>
>
The tests
gcc.target/aarch64/inline-lrint_1.c scan-assembler-times
fcvtzs\tx[0-9]+, d[0-9]+ 3
gcc.target/aarch64/inline-lrint_1.c scan-assembler-times
fcvtzs\tx[0-9]+, s[0-9]+ 3
gcc.target/aarch64/inline-lrint_1.c scan-assembler-times
frintx\td[0-9]+, d[0-9]+ 3
gcc.target/aarch64/inline-lrint_1.c scan-assembler-times
frintx\ts[0-9]+, s[0-9]+ 3
gcc.target/aarch64/no-inline-lrint_1.c scan-assembler-times
frintx\td[0-9]+, d[0-9]+ 3
gcc.target/aarch64/no-inline-lrint_1.c scan-assembler-times
frintx\ts[0-9]+, s[0-9]+ 3
fail on aarch64 bare-metal targets (and pass on aarch64-linux-gnu)