Ping: GAS/ia64: spurious dv conflict

H. J. Lu hjl@lucon.org
Fri Oct 17 19:39:00 GMT 2003


On Thu, Oct 16, 2003 at 10:31:21AM -0700, H. J. Lu wrote:

> It is trickier than I thought. Here is a patch. I had to add
> 
>  // unconditional compares generate a mutex
> -(p3)   cmp.eq.unc p1, p2 = r1, r2
> +(p3)   cmp.eq.unc p1, p2 = r1, r2;;
> 
> Without the stop bit, the new assembler will complain.
> 
> 

Here is an updated patch. I missed the case like

(p0)   cmp.eq.unc p1, p0 = r1, r2;;


H.J.
-------------- next part --------------
gas/

2003-10-17  Andreas Schwab  <schwab@suse.de>
	    H.J. Lu  <hongjiu.lu@intel.com>
	    Jim Wilson <wilson@specifixinc.com>

	* config/tc-ia64.c (update_qp_mutex): New.
	(note_register_values): Properly handle one of PRs in compare
	is PR0. Don't add a mutex relation for .and.orcm/.or.andcm.
	Clear mutex relation for .none/.unc. Don't clear mutex relation
	on predicated compare.

testsuite/

2003-10-17  Andreas Schwab  <schwab@suse.de>
	    H.J. Lu  <hongjiu.lu@intel.com>

	* gas/ia64/dv-mutex-err.s: Add more tests for compare.
	* gas/ia64/dv-mutex.s: Likewise.

	* gas/ia64/dv-mutex-err.l: Updated.
	* gas/ia64/dv-mutex.d: Likewise.

--- gas/config/tc-ia64.c.pred	2003-06-30 08:05:22.000000000 -0700
+++ gas/config/tc-ia64.c	2003-10-17 12:16:17.000000000 -0700
@@ -8726,6 +8726,79 @@ clear_qp_branch_flag (mask)
     }
 }
 
+/* MASK contains 2 and only 2 PRs which are mutually exclusive.  Remove
+   any mutexes which contain one of the PRs and create new ones when
+   needed.  */
+
+static int
+update_qp_mutex (valueT mask)
+{
+  int i, j;
+  int add = 0;
+  valueT m;
+
+  i = 0;
+  while (i < qp_mutexeslen)
+    {
+      if ((qp_mutexes[i].prmask & mask) != 0)
+	{
+	  /* If it destroys and creates the same mutex, do nothing.  */
+	  if (qp_mutexes[i].prmask == mask
+	      && qp_mutexes[i].path == md.path)
+	    {
+	      i++;
+	      add = -1;
+	    }
+	  else
+	    {
+	      if (md.debug_dv)
+		{
+		  fprintf (stderr, "  Clearing mutex relation");
+		  print_prmask (qp_mutexes[i].prmask);
+		  fprintf (stderr, "\n");
+		}
+	      
+	      m = 0;
+	      if (qp_mutexes[i].path == md.path)
+		{
+		  /* If it is a proper subset of the mutex, create a
+		     new mutex.  */
+		  if (add == 0
+		      && (qp_mutexes[i].prmask & mask) == mask)
+		    add = 1;
+		  
+		  m = qp_mutexes[i].prmask & ~mask; 
+		  if (m)
+		    {
+		      for (j = 1; !(m & 1); j++)
+			m >>= 1LL;
+		      
+		      m >>= 1LL;
+		      if (m)
+			{
+			  /* Modify the mutex if there are more than
+			     one PR left.  */
+			  qp_mutexes[i].prmask &= ~mask;
+			  i++;
+			}
+		    }
+		}
+	      
+	      if (m == 0)
+		/* Remove the mutex.  */
+		qp_mutexes[i] = qp_mutexes[--qp_mutexeslen];
+	    }
+	}
+      else
+	++i;
+    }
+
+  if (add == 1)
+    add_qp_mutex (mask);
+
+  return add;
+}
+
 /* Remove any mutexes which contain any of the PRs indicated in the mask.
 
    Any changes to a PR clears the mutex relations which include that PR.  */
@@ -8990,11 +9063,11 @@ note_register_values (idesc)
     {
       int p1 = CURR_SLOT.opnd[0].X_add_number - REG_P;
       int p2 = CURR_SLOT.opnd[1].X_add_number - REG_P;
-      valueT p1mask = (valueT) 1 << p1;
-      valueT p2mask = (valueT) 1 << p2;
+      valueT p1mask = (p1 != 0) ? (valueT) 1 << p1 : 0;
+      valueT p2mask = (p2 != 0) ? (valueT) 1 << p2 : 0;
 
-      /* If one of the PRs is PR0, we can't really do anything.  */
-      if (p1 == 0 || p2 == 0)
+      /* If both PRs are PR0, we can't really do anything.  */
+      if (p1 == 0 && p2 == 0)
 	{
 	  if (md.debug_dv)
 	    fprintf (stderr, "  Ignoring PRs due to inclusion of p0\n");
@@ -9004,7 +9077,6 @@ note_register_values (idesc)
       else if (has_suffix_p (idesc->name, ".or.andcm")
 	       || has_suffix_p (idesc->name, ".and.orcm"))
 	{
-	  add_qp_mutex (p1mask | p2mask);
 	  clear_qp_implies (p2mask, p1mask);
 	}
       else if (has_suffix_p (idesc->name, ".andcm")
@@ -9020,26 +9092,29 @@ note_register_values (idesc)
 	}
       else
 	{
+	  int added = 0;
+
 	  clear_qp_implies (p1mask | p2mask, p1mask | p2mask);
-	  if (has_suffix_p (idesc->name, ".unc"))
+
+	  /* If one of the PRs is PR0, we call clear_qp_mutex.  */
+	  if (p1 == 0 || p2 == 0)
+	    clear_qp_mutex (p1mask | p2mask);
+	  else
+	    added = update_qp_mutex (p1mask | p2mask);
+
+	  if (CURR_SLOT.qp_regno == 0
+	      || has_suffix_p (idesc->name, ".unc"))
 	    {
-	      add_qp_mutex (p1mask | p2mask);
+	      if (added == 0 && p1 && p2)
+		add_qp_mutex (p1mask | p2mask);
 	      if (CURR_SLOT.qp_regno != 0)
 		{
-		  add_qp_imply (CURR_SLOT.opnd[0].X_add_number - REG_P,
-				CURR_SLOT.qp_regno);
-		  add_qp_imply (CURR_SLOT.opnd[1].X_add_number - REG_P,
-				CURR_SLOT.qp_regno);
+		  if (p1)
+		    add_qp_imply (p1, CURR_SLOT.qp_regno);
+		  if (p2)
+		    add_qp_imply (p2, CURR_SLOT.qp_regno);
 		}
 	    }
-	  else if (CURR_SLOT.qp_regno == 0)
-	    {
-	      add_qp_mutex (p1mask | p2mask);
-	    }
-	  else
-	    {
-	      clear_qp_mutex (p1mask | p2mask);
-	    }
 	}
     }
   /* Look for mov imm insns into GRs.  */
--- gas/testsuite/gas/ia64/dv-mutex-err.l.pred	2000-04-23 09:41:25.000000000 -0700
+++ gas/testsuite/gas/ia64/dv-mutex-err.l	2003-10-16 23:24:38.000000000 -0700
@@ -2,3 +2,12 @@
 .*:9: Warning: Use of 'ld8' .* RAW dependency 'GR%, % in 1 - 127' \(impliedf\), specific resource number is 26
 .*:9: Warning: Only the first path encountering the conflict is reported
 .*:8: Warning: This is the location of the conflicting usage
+.*:14: Warning: Use of 'mov' may violate WAW dependency 'GR%, % in 1 - 127' \(impliedf\), specific resource number is 4
+.*:14: Warning: Only the first path encountering the conflict is reported
+.*:13: Warning: This is the location of the conflicting usage
+.*:20: Warning: Use of 'mov' may violate WAW dependency 'GR%, % in 1 - 127' \(impliedf\), specific resource number is 4
+.*:19: Warning: This is the location of the conflicting usage
+.*:26: Warning: Use of 'mov' may violate WAW dependency 'GR%, % in 1 - 127' \(impliedf\), specific resource number is 4
+.*:25: Warning: This is the location of the conflicting usage
+.*:32: Warning: Use of 'mov' may violate WAW dependency 'GR%, % in 1 - 127' \(impliedf\), specific resource number is 4
+.*:31: Warning: This is the location of the conflicting usage
--- gas/testsuite/gas/ia64/dv-mutex-err.s.pred	2000-04-23 09:41:25.000000000 -0700
+++ gas/testsuite/gas/ia64/dv-mutex-err.s	2003-10-16 23:24:38.000000000 -0700
@@ -7,3 +7,27 @@ start:	
 	cmp.eq	p6, p0 = r29, r0
 	add	r26 = r26, r29
 	ld8	r29 = [r26]
+
+	.pred.rel.mutex p1, p2
+	cmp.eq p0, p1 = r1, r2;;
+(p1)	mov r4 = 2
+(p2)	mov r4 = 4
+	rfi
+
+	.pred.rel.mutex p1, p2
+(p3)	cmp.eq p0, p1 = r1, r2;;
+(p1)	mov r4 = 2
+(p2)	mov r4 = 4
+	rfi
+
+	.pred.rel.mutex p1, p2
+	cmp.eq p2, p3 = r1, r2;;
+(p1)	mov r4 = 2
+(p2)	mov r4 = 4
+	rfi
+
+	.pred.rel.mutex p1, p2
+(p3)	cmp.eq p2, p3 = r1, r2;;
+(p1)	mov r4 = 2
+(p2)	mov r4 = 4
+	rfi
--- gas/testsuite/gas/ia64/dv-mutex.d.pred	2003-09-25 21:07:48.000000000 -0700
+++ gas/testsuite/gas/ia64/dv-mutex.d	2003-10-16 23:24:38.000000000 -0700
@@ -19,9 +19,21 @@ Disassembly of section \.text:
   30:	1d 00 00 00 01 00 	\[MFB\]       nop\.m 0x0
   36:	00 00 00 02 00 00 	            nop\.f 0x0
   3c:	00 00 20 00       	            rfi;;
-  40:	60 08 06 04 02 78 	\[MII\] \(p03\) cmp\.eq\.unc p1,p2=r1,r2
+  40:	6a 08 06 04 02 78 	\[MMI\] \(p03\) cmp\.eq\.unc p1,p2=r1,r2;;
   46:	40 10 00 00 42 81 	      \(p01\) mov r4=2
   4c:	40 00 00 84       	      \(p02\) mov r4=4
   50:	1d 00 00 00 01 00 	\[MFB\]       nop\.m 0x0
   56:	00 00 00 02 00 00 	            nop\.f 0x0
   5c:	00 00 20 00       	            rfi;;
+  60:	0a 08 04 04 02 78 	\[MMI\]       cmp\.eq p1,p2=r1,r2;;
+  66:	40 10 00 00 42 81 	      \(p01\) mov r4=2
+  6c:	40 00 00 84       	      \(p02\) mov r4=4
+  70:	1d 00 00 00 01 00 	\[MFB\]       nop\.m 0x0
+  76:	00 00 00 02 00 00 	            nop\.f 0x0
+  7c:	00 00 20 00       	            rfi;;
+  80:	6a 08 04 04 02 78 	\[MMI\] \(p03\) cmp\.eq p1,p2=r1,r2;;
+  86:	40 10 00 00 42 81 	      \(p01\) mov r4=2
+  8c:	40 00 00 84       	      \(p02\) mov r4=4
+  90:	1d 00 00 00 01 00 	\[MFB\]       nop\.m 0x0
+  96:	00 00 00 02 00 00 	            nop\.f 0x0
+  9c:	00 00 20 00       	            rfi;;
--- gas/testsuite/gas/ia64/dv-mutex.s.pred	2000-09-02 09:58:33.000000000 -0700
+++ gas/testsuite/gas/ia64/dv-mutex.s	2003-10-16 23:24:38.000000000 -0700
@@ -17,7 +17,19 @@ start:	
 	rfi
 
 // unconditional compares generate a mutex
-(p3)	cmp.eq.unc p1, p2 = r1, r2
+(p3)	cmp.eq.unc p1, p2 = r1, r2;;
+(p1)	mov r4 = 2
+(p2)	mov r4 = 4
+	rfi
+
+// non-predicated compares don't remove mutex
+	cmp.eq p1, p2 = r1, r2;;
+(p1)	mov r4 = 2
+(p2)	mov r4 = 4
+	rfi
+
+// predicated compares don't remove mutex
+(p3)	cmp.eq p1, p2 = r1, r2;;
 (p1)	mov r4 = 2
 (p2)	mov r4 = 4
 	rfi


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