re PR target/52125 (Problems with LO16 asm operands on MIPS)

gcc/
	PR target/52125
	* rtl.h (get_referenced_operands): Declare.
	* recog.c (get_referenced_operands): New function.
	* config/mips/mips.c (mips_reorg_process_insns): Check which asm
	operands have been referenced when recording LO_SUM references.

gcc/testsuite/
	PR target/52125
	* gcc.dg/pr48774.c: Remove skip for mips_rel.
	* gcc.target/mips/pr52125.c: New test.

From-SVN: r206955

gcc/ChangeLog

+2014-01-23  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	PR target/52125
+	* rtl.h (get_referenced_operands): Declare.
+	* recog.c (get_referenced_operands): New function.
+	* config/mips/mips.c (mips_reorg_process_insns): Check which asm
+	operands have been referenced when recording LO_SUM references.
+
 2014-01-22  David Holsgrove <david.holsgrove@xilinx.com>
 
 	* config/microblaze/microblaze.md: Correct bswaphi2 insn.

gcc/config/mips/mips.c

@@ -16097,7 +16097,23 @@ mips_reorg_process_insns (void)
   for (insn = get_insns (); insn != 0; insn = NEXT_INSN (insn))
     FOR_EACH_SUBINSN (subinsn, insn)
       if (USEFUL_INSN_P (subinsn))
-	for_each_rtx (&PATTERN (subinsn), mips_record_lo_sum, &htab);
+	{
+	  rtx body = PATTERN (insn);
+	  int noperands = asm_noperands (body);
+	  if (noperands >= 0)
+	    {
+	      rtx *ops = XALLOCAVEC (rtx, noperands);
+	      bool *used = XALLOCAVEC (bool, noperands);
+	      const char *string = decode_asm_operands (body, ops, NULL, NULL,
+							NULL, NULL);
+	      get_referenced_operands (string, used, noperands);
+	      for (int i = 0; i < noperands; ++i)
+		if (used[i])
+		  for_each_rtx (&ops[i], mips_record_lo_sum, &htab);
+	    }
+	  else
+	    for_each_rtx (&PATTERN (subinsn), mips_record_lo_sum, &htab);
+	}
 
   last_insn = 0;
   hilo_delay = 2;

gcc/recog.c

@@ -1620,6 +1620,50 @@ decode_asm_operands (rtx body, rtx *operands, rtx **operand_locs,
   return ASM_OPERANDS_TEMPLATE (asmop);
 }
 
+/* Parse inline assembly string STRING and determine which operands are
+   referenced by % markers.  For the first NOPERANDS operands, set USED[I]
+   to true if operand I is referenced.
+
+   This is intended to distinguish barrier-like asms such as:
+
+      asm ("" : "=m" (...));
+
+   from real references such as:
+
+      asm ("sw\t$0, %0" : "=m" (...));  */
+
+void
+get_referenced_operands (const char *string, bool *used,
+			 unsigned int noperands)
+{
+  memset (used, 0, sizeof (bool) * noperands);
+  const char *p = string;
+  while (*p)
+    switch (*p)
+      {
+      case '%':
+	p += 1;
+	/* A letter followed by a digit indicates an operand number.  */
+	if (ISALPHA (p[0]) && ISDIGIT (p[1]))
+	  p += 1;
+	if (ISDIGIT (*p))
+	  {
+	    char *endptr;
+	    unsigned long opnum = strtoul (p, &endptr, 10);
+	    if (endptr != p && opnum < noperands)
+	      used[opnum] = true;
+	    p = endptr;
+	  }
+	else
+	  p += 1;
+	break;
+
+      default:
+	p++;
+	break;
+      }
+}
+
 /* Check if an asm_operand matches its constraints.
    Return > 0 if ok, = 0 if bad, < 0 if inconclusive.  */
 

gcc/rtl.h

@@ -2169,6 +2169,7 @@ extern rtx extract_asm_operands (rtx);
 extern int asm_noperands (const_rtx);
 extern const char *decode_asm_operands (rtx, rtx *, rtx **, const char **,
 					enum machine_mode *, location_t *);
+extern void get_referenced_operands (const char *, bool *, unsigned int);
 
 extern enum reg_class reg_preferred_class (int);
 extern enum reg_class reg_alternate_class (int);

gcc/testsuite/ChangeLog

+2014-01-23  Richard Sandiford  <rdsandiford@googlemail.com>
+
+	PR target/52125
+	* gcc.dg/pr48774.c: Remove skip for mips_rel.
+	* gcc.target/mips/pr52125.c: New test.
+
 2014-01-22  Marek Polacek  <polacek@redhat.com>
 
 	PR c/59891

gcc/testsuite/gcc.dg/pr48774.c

 /* PR target/48774 */
 /* { dg-do run } */
-/* { dg-skip-if "PR 52125" { mips_rel } { "*" } { "" } } */
 /* { dg-options "-O2 -funroll-loops" } */
 
 extern void abort (void);

gcc/testsuite/gcc.target/mips/pr52125.c

+/* { dg-options "addressing=absolute" } */
+
+int a, b, c, d;
+
+NOMIPS16 void
+foo (void)
+{
+  asm ("%1 %z3"
+       : "=m" (a), "=m" (b)
+       : "m" (c), "m" (d));
+}
+
+/* { dg-final { scan-assembler-not "%hi\\(a\\)" } } */
+/* { dg-final { scan-assembler-not "%lo\\(a\\)" } } */
+/* { dg-final { scan-assembler "%hi\\(b\\)" } } */
+/* { dg-final { scan-assembler "%lo\\(b\\)" } } */
+/* { dg-final { scan-assembler-not "%hi\\(c\\)" } } */
+/* { dg-final { scan-assembler-not "%lo\\(c\\)" } } */
+/* { dg-final { scan-assembler "%hi\\(d\\)" } } */
+/* { dg-final { scan-assembler "%lo\\(d\\)" } } */