Re: [PATCH V4 2/2] rs6000: use li;x?oris to build constant

[guojiufu via Gcc-patches]

Hi,

On 2023-05-15 14:53, Kewen.Lin wrote:

Hi Jeff,

on 2022/12/12 09:38, Jiufu Guo wrote:

Hi,

For constant C:
If '(c & 0xFFFFFFFF0000FFFFULL) == 0xFFFFFFFF00000000' or say:
32(1) || 1(0) || 15(x) || 16(0), we could use "lis; xoris" to build.

Here N(M) means N continuous bit M, x for M means it is ok for either
1 or 0; '||' means concatenation.

This patch update rs6000_emit_set_long_const to support those constants.

Compare with previous version:
https://gcc.gnu.org/pipermail/gcc-patches/2022-December/607618.htm
This patch fix conflicts with trunk.

Bootstrap and regtest pass on ppc64{,le}.

Is this ok for trunk?

OK for trunk, thanks for improving this.

btw, the test case needs to be updated a bit as the function names in the context changed upstream, please ensure it's tested well before committing,

thanks!

Yeap! Retested and verified.
Thanks so much for your always insight review and helpful comments!

Committed via r14-923-g5eb7d560626e42.

BR,
Jeff (Jiufu)

BR,
Jeff (Jiufu)


        PR target/106708

gcc/ChangeLog:

        * config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Add to build
        constants through "lis; xoris".

Maybe s/Add to build/Support building/

Yes :)

BR,
Kewen

gcc/testsuite/ChangeLog:

        * gcc.target/powerpc/pr106708.c: Add test function.

---
 gcc/config/rs6000/rs6000.cc                 |  7 +++++++
 gcc/testsuite/gcc.target/powerpc/pr106708.c | 10 +++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 8c1192a10c8..1138d5e8cd4 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc

@@ -10251,6 +10251,13 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)

       if (ud1 != 0)
        emit_move_insn (dest, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
     }

+ else if (ud4 == 0xffff && ud3 == 0xffff && !(ud2 & 0x8000) && ud1 == 0)

+    {
+      /* lis; xoris */
+      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);

+ emit_move_insn (temp, GEN_INT (sext_hwi ((ud2 | 0x8000) << 16, 32))); + emit_move_insn (dest, gen_rtx_XOR (DImode, temp, GEN_INT (0x80000000)));

+    }
   else if (ud4 == 0xffff && ud3 == 0xffff && (ud1 & 0x8000))
     {
       /* li; xoris */

diff --git a/gcc/testsuite/gcc.target/powerpc/pr106708.c b/gcc/testsuite/gcc.target/powerpc/pr106708.c

index dc9ceda8367..a015c71e630 100644
--- a/gcc/testsuite/gcc.target/powerpc/pr106708.c
+++ b/gcc/testsuite/gcc.target/powerpc/pr106708.c
@@ -4,7 +4,7 @@
 /* { dg-require-effective-target has_arch_ppc64 } */

 long long arr[]
-  = {0xffffffff7cdeab55LL, 0x98765432LL, 0xabcd0000LL};

+= {0xffffffff7cdeab55LL, 0x98765432LL, 0xabcd0000LL, 0xffffffff65430000LL};

 void __attribute__ ((__noipa__)) lixoris (long long *arg)
 {

@@ -27,6 +27,13 @@ void __attribute__ ((__noipa__)) lisrldicl (long long *arg)

 /* { dg-final { scan-assembler-times {\mlis .*,0xabcd\M} 1 } } */
 /* { dg-final { scan-assembler-times {\mrldicl .*,0,32\M} 1 } } */

+void __attribute__ ((__noipa__)) lisxoris (long long *arg)
+{
+  *arg = 0xffffffff65430000LL;
+}
+/* { dg-final { scan-assembler-times {\mlis .*,0xe543\M} 1 } } */
+/* { dg-final { scan-assembler-times {\mxoris .*0x8000\M} 1 } } */
+
 int
 main ()
 {
@@ -35,6 +42,7 @@ main ()
   lixoris (a);
   lioris (a + 1);
   lisrldicl (a + 2);
+  lisxoris (a + 3);
   if (__builtin_memcmp (a, arr, sizeof (arr)) != 0)
     __builtin_abort ();
   return 0;