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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@206955 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 44 insertions, 0 deletions

diff --git a/gcc/recog.c b/gcc/recog.c
index b81214cf41c..e2caf9859d8 100644
--- a/gcc/recog.c
+++ b/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.  */