On 1/14/22 10:54, Roger Sayle wrote:
Now that the middle-end MULT_HIGHPART_EXPR pieces are in place, this
patch adds support for nvptx's mul.hi.s64 and mul.hi.u64 instructions,
as previously reviewed (provisionally pre-approved) back in August 2020:
https://gcc.gnu.org/pipermail/gcc-patches/2020-August/551373.html
Since then a few things have changed, so this patch uses the new
SMUL_HIGHPART and UMUL_HIGHPART RTX expressions, but the test cases
remain the same. Like the x86_64 backend, this patch retains the
"trunc" forms of these instructions (while the RTL optimizers/combine
may still generate them).
Given that we're rapidly approaching stage 4, I also took the liberty
of including support in nvptx.md for a few other instructions. With
the new 64-bit highpart multiplication instructions added above, we
can now provide a define_expand for efficient 64-bit (to 128-bit)
widening multiplications. This patch also adds support for nvptx's
testp.infinite instruction (for implementing __builtin_isinf) and
the not.pred instruction.
As an example of the code generation improvements, the function
int foo(double x) { return __builtin_isinf(x); }
previously generated with -O2:
mov.f64 %r26, %ar0;
abs.f64 %r28, %r26;
setp.leu.f64 %r31, %r28, 0d7fefffffffffffff;
selp.u32 %r30, 1, 0, %r31;
mov.u32 %r29, %r30;
cvt.u16.u8 %r35, %r29;
mov.u16 %r33, %r35;
xor.b16 %r32, %r33, 1;
cvt.u32.u16 %r34, %r32;
cvt.u32.u8 %value, %r34;
and with this patch now generates:
mov.f64 %r23, %ar0;
testp.infinite.f64 %r24, %r23;
selp.u32 %value, 1, 0, %r24;
This patch has been tested on nvptx-none hosted on x86_64-pc-linux-gnu
(including newlib) with a make and make -k check with no new failures.
Ok for mainline?
LGTM, applied.
Thanks,
- Tom
2022-01-14 Roger Sayle <ro...@nextmovesoftware.com>
gcc/ChangeLog
* config/nvptx/nvptx.md (UNSPEC_ISINF): New UNSPEC.
(one_cmplbi2): New define_insn for not.pred.
(mulditi3): New define_expand for signed widening multiply.
(umulditi3): New define_expand for unsigned widening multiply.
(smul<mode>3_highpart): New define_insn for signed highpart mult.
(umul<mode>3_highpart): New define_insn for unsigned highpart mult.
(*smulhi3_highpart_2): Renamed from smulhi3_highpart.
(*smulsi3_highpart_2): Renamed from smulsi3_highpart.
(*umulhi3_highpart_2): Renamed from umulhi3_highpart.
(*umulsi3_highpart_2): Renamed from umulsi3_highpart.
(*setcc<mode>_from_not_bi): New define_insn.
(*setcc_isinf<mode>): New define_insn for testp.infinite.
(isinf<mode>2): New define_expand.
gcc/testsuite/ChangeLog
* gcc.target/nvptx/mul-hi64.c: New test case.
* gcc.target/nvptx/umul-hi64.c: New test case.
* gcc.target/nvptx/mul-wide64.c: New test case.
* gcc.target/nvptx/umul-wide64.c: New test case.
* gcc.target/nvptx/isinf.c: New test case.
Thanks in advance,
Roger
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