[1/2] rs6000: use lis;xoris to build constant
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Commit Message
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.
Bootstrap and regtest pass on ppc64{,le}.
Is this ok for trunk?
BR,
Jeff (Jiufu)
PR target/106708
gcc/ChangeLog:
* config/rs6000/rs6000.cc (rs6000_emit_set_long_const): Add to build
constants through "lis; xoris".
gcc/testsuite/ChangeLog:
* gcc.target/powerpc/pr106708.c: New test.
---
gcc/config/rs6000/rs6000.cc | 7 +++++++
gcc/testsuite/gcc.target/powerpc/pr106708.c | 23 +++++++++++++++++++++
2 files changed, 30 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/powerpc/pr106708.c
@@ -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 (ud3 == 0 && ud4 == 0)
{
temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
new file mode 100644
@@ -0,0 +1,23 @@
+/* PR target/106708 */
+/* { dg-do run } */
+/* { dg-options "-O2 -mno-prefixed -save-temps" } */
+/* { dg-require-effective-target has_arch_ppc64 } */
+
+long long arr[] = {0xffffffff65430000LL};
+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 ()
+{
+ long long a[sizeof (arr) / sizeof (arr[0])];
+
+ lisxoris (a);
+ if (__builtin_memcmp (a, arr, sizeof (arr)) != 0)
+ __builtin_abort ();
+ return 0;
+}