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rs6000: use lis;xoris to build constant

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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/608292.html
This patch updates test function names only.

Bootstrap and regtest pass on ppc64{,le}.

	PR target/106708

gcc/ChangeLog:

	* config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Support building
	constants through "lis; xoris".

gcc/testsuite/ChangeLog:

	* gcc.target/powerpc/pr106708.c: Add test function.
This commit is contained in:
Jiufu Guo 2022-12-10 21:18:51 +08:00
parent 0d56605751
commit 5eb7d56062
2 changed files with 16 additions and 1 deletions
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7
gcc/config/rs6000/rs6000.cc
View file

@ -10289,6 +10289,13 @@ 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 */

10
gcc/testsuite/gcc.target/powerpc/pr106708.c
View file

@ -4,7 +4,7 @@
/* { dg-require-effective-target has_arch_ppc64 } */
long long arr[]
= {0xffffffff7cdeab55LL, 0x98765432LL, 0xabcd0000LL};
= {0xffffffff7cdeab55LL, 0x98765432LL, 0xabcd0000LL, 0xffffffff65430000LL};
void __attribute__ ((__noipa__)) test_li_xoris (long long *arg)
{
@ -27,6 +27,13 @@ void __attribute__ ((__noipa__)) test_lis_rldicl (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__)) test_lis_xoris (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 ()
test_li_xoris (a);
test_li_oris (a + 1);
test_lis_rldicl (a + 2);
test_lis_xoris (a + 3);
if (__builtin_memcmp (a, arr, sizeof (arr)) != 0)
__builtin_abort ();
return 0;