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

Jiufu Guo guojiufu@linux.ibm.com
Thu Dec 1 08:47:54 GMT 2022


Hi,

For constant C:
If '(c & 0xFFFFFFFF00008000ULL) == 0xFFFFFFFF00008000ULL' or say:
32(1) || 16(x) || 1(1) || 15(x), using "li; xoris" would be ok.

If '(c & 0xFFFFFFFF80008000ULL) == 0x80000000ULL' or say:
32(0) || 1(1) || 15(x) || 1(0) || 15(x), we could use "li; oris" to
build constant 'C'.

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 building
	constants through "li; x?oris".

gcc/testsuite/ChangeLog:

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

---
 gcc/config/rs6000/rs6000.cc                 | 34 ++++++++++++++++++---
 gcc/testsuite/gcc.target/powerpc/pr106708.c | 27 +++++++++++++++-
 2 files changed, 56 insertions(+), 5 deletions(-)

diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
index 7efed94a0bc..316ee97c53d 100644
--- a/gcc/config/rs6000/rs6000.cc
+++ b/gcc/config/rs6000/rs6000.cc
@@ -10251,6 +10251,14 @@ 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 && (ud1 & 0x8000))
+    {
+      /* li; xoris */
+      temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
+      emit_move_insn (temp, GEN_INT (sext_hwi (ud1, 16)));
+      emit_move_insn (dest, gen_rtx_XOR (DImode, temp,
+					 GEN_INT ((ud2 ^ 0xffff) << 16)));
+    }
   else if (ud4 == 0xffff && ud3 == 0xffff && !(ud2 & 0x8000) && ud1 == 0)
     {
       /* lis; xoris */
@@ -10263,10 +10271,28 @@ rs6000_emit_set_long_const (rtx dest, HOST_WIDE_INT c)
       temp = !can_create_pseudo_p () ? dest : gen_reg_rtx (DImode);
 
       gcc_assert (ud2 & 0x8000);
-      emit_move_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
-      if (ud1 != 0)
-	emit_move_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
-      emit_move_insn (dest, gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff)));
+
+      if (ud1 == 0)
+	{
+	  /* lis; rldicl */
+	  emit_move_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
+	  emit_move_insn (dest,
+			  gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff)));
+	}
+      else if (!(ud1 & 0x8000))
+	{
+	  /* li; oris */
+	  emit_move_insn (temp, GEN_INT (ud1));
+	  emit_move_insn (dest,
+			  gen_rtx_IOR (DImode, temp, GEN_INT (ud2 << 16)));
+	}
+      else
+	{
+	  emit_move_insn (temp, GEN_INT (sext_hwi (ud2 << 16, 32)));
+	  emit_move_insn (temp, gen_rtx_IOR (DImode, temp, GEN_INT (ud1)));
+	  emit_move_insn (dest,
+			  gen_rtx_AND (DImode, temp, GEN_INT (0xffffffff)));
+	}
     }
   else if (ud1 == ud3 && ud2 == ud4)
     {
diff --git a/gcc/testsuite/gcc.target/powerpc/pr106708.c b/gcc/testsuite/gcc.target/powerpc/pr106708.c
index dd0386c109c..fd1e1cab8fc 100644
--- a/gcc/testsuite/gcc.target/powerpc/pr106708.c
+++ b/gcc/testsuite/gcc.target/powerpc/pr106708.c
@@ -3,7 +3,8 @@
 /* { dg-options "-O2 -mno-prefixed -save-temps" } */
 /* { dg-require-effective-target has_arch_ppc64 } */
 
-long long arr[] = {0xffffffff65430000LL};
+long long arr[]
+  = {0xffffffff65430000LL, 0xffffffff7cdeab55LL, 0x98765432LL, 0xabcd0000LL};
 void __attribute__ ((__noipa__)) lisxoris (long long *arg)
 {
   *arg = 0xffffffff65430000LL;
@@ -11,12 +12,36 @@ void __attribute__ ((__noipa__)) lisxoris (long long *arg)
 /* { dg-final { scan-assembler-times {\mlis .*,0xe543\M} 1 } } */
 /* { dg-final { scan-assembler-times {\mxoris .*0x8000\M} 1 } } */
 
+void __attribute__ ((__noipa__)) lixoris (long long *arg)
+{
+  *arg = 0xffffffff7cdeab55LL;
+}
+/* { dg-final { scan-assembler-times {\mli .*,-21675\M} 1 } } */
+/* { dg-final { scan-assembler-times {\mxoris .*0x8321\M} 1 } } */
+
+void __attribute__ ((__noipa__)) lioris (long long *arg)
+{
+  *arg = 0x98765432LL;
+}
+/* { dg-final { scan-assembler-times {\mli .*,21554\M} 1 } } */
+/* { dg-final { scan-assembler-times {\moris .*0x9876\M} 1 } } */
+
+void __attribute__ ((__noipa__)) lisrldicl (long long *arg)
+{
+  *arg = 0xabcd0000LL;
+}
+/* { dg-final { scan-assembler-times {\mlis .*,0xabcd\M} 1 } } */
+/* { dg-final { scan-assembler-times {\mrldicl .*,0,32\M} 1 } } */
+
 int
 main ()
 {
   long long a[sizeof (arr) / sizeof (arr[0])];
 
   lisxoris (a);
+  lixoris (a + 1);  
+  lioris (a + 2);
+  lisrldicl (a + 3);
   if (__builtin_memcmp (a, arr, sizeof (arr)) != 0)
     __builtin_abort ();
   return 0;
-- 
2.17.1



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