On Wed, Apr 6, 2022 at 5:56 AM Roger Sayle <ro...@nextmovesoftware.com> wrote:
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> This simple patch allows the i386 backend to generate pandn instructions
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> for V1TI mode. Currently, the testcase:
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> typedef unsigned __int128 v1ti __attribute__ ((__vector_size__ (16)));
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> v1ti andnot1(v1ti x, v1ti y) { return ~x & y; }
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> generates with -O2
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> pcmpeqd %xmm2, %xmm2
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> pxor %xmm2, %xmm0
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> pand %xmm1, %xmm0
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> ret
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> with this patch, we now generate:
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> pandn %xmm1, %xmm0
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> ret
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> It turns out that there are currently three (near) duplicates of the
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> logic for andn/pandn/vandn/vpandn in i386/sse.md: one for floating point
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> vectors (MODEF), one for integer vectors (VI) and a third for TFmode.
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> Rather than introduce a fourth copy, this patch introduces a new mode
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> iterator to share/reuse the TFmode define_insn to also handle V1TI.
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> This patch has been tested on x86_64-pc-linux-gnu with make bootstrap
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> and make -k check with no new failures. Ok for mainline?
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Ok.
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> 2022-04-05 Roger Sayle <ro...@nextmovesoftware.com>
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> gcc/ChangeLog
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> * config/i386/sse.md (ANDNOT_MODE): New mode iterator for TF and V1TI.
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> (*andnottf3): Replace with...
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> (*andnot<mode>3): New define_insn using ANDNOT_MODE.
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> gcc/testsuite/ChangeLog
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> * gcc.target/i386/sse2-v1ti-andnot.c: New test case.
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> Thanks in advance,
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> Roger
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> --
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--
BR,
Hongtao
