re PR target/91769 (wrong code with -O2 on MIPS)

Fix PR target/91769

This fixes the issue by checking that addr's base reg is not part of dest
multiword reg instead just checking the first reg of dest.

gcc/ChangeLog:

2019-10-03  Dragan Mladjenovic  <dmladjenovic@wavecomp.com>

	PR target/91769
	* config/mips/mips.c (mips_split_move): Use reg_overlap_mentioned_p
	instead of REGNO equality check on addr.reg.

gcc/testsuite/ChangeLog:

2019-10-03  Dragan Mladjenovic  <dmladjenovic@wavecomp.com>

	PR target/91769
	* gcc.target/mips/pr91769.c: New test.

From-SVN: r276525

gcc/ChangeLog

+2019-10-03  Dragan Mladjenovic  <dmladjenovic@wavecomp.com>
+
+	PR target/91769
+	* config/mips/mips.c (mips_split_move): Use reg_overlap_mentioned_p
+	instead of REGNO equality check on addr.reg.
+
 2019-10-03  Jan Hubicka  <hubicka@ucw.cz>
 
 	* params.def (PARAM_INLINE_HEURISTICS_HINT_PERCENT,

gcc/config/mips/mips.c

@@ -4862,7 +4862,7 @@ mips_split_move (rtx dest, rtx src, enum mips_split_type split_type, rtx insn_)
 		{
 		  rtx tmp = XEXP (src, 0);
 		  mips_classify_address (&addr, tmp, GET_MODE (tmp), true);
-		  if (addr.reg && REGNO (addr.reg) != REGNO (dest))
+		  if (addr.reg && !reg_overlap_mentioned_p (dest, addr.reg))
 		    validate_change (next, &SET_SRC (set), src, false);
 		}
 	      else

gcc/testsuite/ChangeLog

+2019-10-03  Dragan Mladjenovic  <dmladjenovic@wavecomp.com>
+
+	PR target/91769
+	* gcc.target/mips/pr91769.c: New test.
+
 2019-10-03  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* g++.dg/cpp0x/gen-attrs-67.C: Expect constructor priorities error

gcc/testsuite/gcc.target/mips/pr91769.c

+/* PR target/91769 */
+/* { dg-do compile } */
+/* { dg-skip-if "naming registers makes this a code quality test" { *-*-* } { "-O0" "-g" } { "" } } */
+/* { dg-options "-EL -mgp32 -mhard-float" } */
+
+NOCOMPRESSION double
+foo (void)
+{
+  register double* pf __asm__ ("$a1");
+  __asm__ __volatile__ ("":"=r"(pf));
+  double f = *pf;
+
+  if (f != f)
+    f = -f;
+  return f;
+}
+
+/* { dg-final { scan-assembler-not "lw\t\\\$4,0\\(\\\$5\\)\n\tlw\t\\\$5,4\\(\\\$5\\)\n\tldc1\t\\\$.*,0\\(\\\$5\\)" } } */
+/* { dg-final { scan-assembler "lw\t\\\$4,0\\(\\\$5\\)\n\tlw\t\\\$5,4\\(\\\$5\\)\n\tmtc1\t\\\$4,\\\$.*\n\tmthc1\t\\\$5,\\\$.*" } } */