On 8/27/21 12:07 PM, Roger Sayle wrote:
>
> This patch introduces some new define_insn rules to the nvptx backend,
> to perform sign-extension of a truncation (from and to the same mode),
> using a single cvt instruction. As an example, the following function
>
> int foo(int x) { return (char)x; }
>
> with -O2 currently generates:
>
> mov.u32 %r24, %ar0;
> mov.u32 %r26, %r24;
> cvt.s32.s8 %value, %r26;
>
> and with this patch, now generates:
>
> mov.u32 %r24, %ar0;
> cvt.s32.s8 %value, %r24;
>
> This patch has been tested on nvptx-none hosted by x86_64-pc-linux-gnu
> with a top-level "make" (including newlib) and a "make check" with no
> new regressions. Ok for mainline?
>
Hi Roger,
thanks for the patch and apologies for the delay.
I was not happy with negative-testing-only in the test-case, so I've
split it up into 6 separate tests.
The first one is not influenced by the patch, so I've committed that one
separately.
The other 5 I've committed together with the patch.
Thanks,
- Tom
>
> 2021-08-27 Roger Sayle <ro...@nextmovesoftware.com>
>
> gcc/ChangeLog
> * config/nvptx/nvptx.md (*extend_trunc_<mode>2_qi,
> *extend_trunc_<mode>2_hi, *extend_trunc_di2_si): New insns.
> Use cvt to perform sign-extension of truncation in one step.
>
> gcc/testsuite/ChangeLog
> * gcc.target/nvptx/exttrunc.c: New test case.
>
>
> Roger
> --
>
