Re: Fix regrename compare-debug issue

2016-05-09 Thread Bernd Schmidt 



On 05/05/2016 09:02 AM, Eric Botcazou wrote:

When scanning addresses inside a debug insn, we shouldn't use normal
base/index classes. This shows as a compare-debug issue on Alpha, where
INDEX_REG_CLASS is NO_REGS, and this prevented a chain from being
renamed with debugging turned on.

Uros has reported that this patch resolves the issues he was seeing on
Alpha, and I've bootstrapped and tested it on x86_64-linux. Ok?


OK, thanks.  It might worthwhile to add a sentence somewhere (maybe at the end
of the head comment of the file) documenting the special treatment applied to
debug insns during the pass.


Committed with the extra hunk below.


Bernd

@@ -61,7 +61,10 @@
  5. If a renaming register has been found, it is substituted in 
the chain.


   Targets can parameterize the pass by specifying a preferred class 
for the
-  renaming register for a given (super)class of registers to be 
renamed.  */

+  renaming register for a given (super)class of registers to be renamed.
+
+  DEBUG_INSNs are treated specially, in particular registers occurring 
inside

+  them are treated as requiring ALL_REGS as a class.  */

 #if HOST_BITS_PER_WIDE_INT <= MAX_RECOG_OPERANDS
 #error "Use a different bitmap implementation for untracked_operands."

Re: Fix regrename compare-debug issue

2016-05-05 Thread Eric Botcazou 
> When scanning addresses inside a debug insn, we shouldn't use normal
> base/index classes. This shows as a compare-debug issue on Alpha, where
> INDEX_REG_CLASS is NO_REGS, and this prevented a chain from being
> renamed with debugging turned on.
> 
> Uros has reported that this patch resolves the issues he was seeing on
> Alpha, and I've bootstrapped and tested it on x86_64-linux. Ok?

OK, thanks.  It might worthwhile to add a sentence somewhere (maybe at the end 
of the head comment of the file) documenting the special treatment applied to 
debug insns during the pass.

-- 
Eric Botcazou

Fix regrename compare-debug issue

2016-05-04 Thread Bernd Schmidt 
When scanning addresses inside a debug insn, we shouldn't use normal 
base/index classes. This shows as a compare-debug issue on Alpha, where 
INDEX_REG_CLASS is NO_REGS, and this prevented a chain from being 
renamed with debugging turned on.


Uros has reported that this patch resolves the issues he was seeing on 
Alpha, and I've bootstrapped and tested it on x86_64-linux. Ok?



Bernd
	* regrename.c (base_reg_class_for_rename): New static function.
	(scan_rtx_address, scan_rtx): Use it instead of base_reg_class.

Index: gcc/regrename.c
===
--- gcc/regrename.c	(revision 235808)
+++ gcc/regrename.c	(working copy)
@@ -1238,6 +1238,19 @@ scan_rtx_reg (rtx_insn *insn, rtx *loc,
 }
 }
 
+/* A wrapper around base_reg_class which returns ALL_REGS if INSN is a
+   DEBUG_INSN.  The arguments MODE, AS, CODE and INDEX_CODE are as for
+   base_reg_class.  */
+
+static reg_class
+base_reg_class_for_rename (rtx_insn *insn, machine_mode mode, addr_space_t as,
+			   rtx_code code, rtx_code index_code)
+{
+  if (DEBUG_INSN_P (insn))
+return ALL_REGS;
+  return base_reg_class (mode, as, code, index_code);
+}
+
 /* Adapted from find_reloads_address_1.  CL is INDEX_REG_CLASS or
BASE_REG_CLASS depending on how the register is being considered.  */
 
@@ -1343,12 +1356,16 @@ scan_rtx_address (rtx_insn *insn, rtx *l
 	  }
 
 	if (locI)
-	  scan_rtx_address (insn, locI, INDEX_REG_CLASS, action, mode, as);
+	  {
+	reg_class iclass = DEBUG_INSN_P (insn) ? ALL_REGS : INDEX_REG_CLASS;
+	scan_rtx_address (insn, locI, iclass, action, mode, as);
+	  }
 	if (locB)
-	  scan_rtx_address (insn, locB,
-			base_reg_class (mode, as, PLUS, index_code),
-			action, mode, as);
-
+	  {
+	reg_class bclass = base_reg_class_for_rename (insn, mode, as, PLUS,
+			  index_code);
+	scan_rtx_address (insn, locB, bclass, action, mode, as);
+	  }
 	return;
   }
 
@@ -1366,10 +1383,13 @@ scan_rtx_address (rtx_insn *insn, rtx *l
   break;
 
 case MEM:
-  scan_rtx_address (insn,  (x, 0),
-			base_reg_class (GET_MODE (x), MEM_ADDR_SPACE (x),
-	MEM, SCRATCH),
-			action, GET_MODE (x), MEM_ADDR_SPACE (x));
+  {
+	reg_class bclass = base_reg_class_for_rename (insn, GET_MODE (x),
+		  MEM_ADDR_SPACE (x),
+		  MEM, SCRATCH);
+	scan_rtx_address (insn,  (x, 0), bclass, action, GET_MODE (x),
+			  MEM_ADDR_SPACE (x));
+  }
   return;
 
 case REG:
@@ -1416,10 +1436,14 @@ scan_rtx (rtx_insn *insn, rtx *loc, enum
   return;
 
 case MEM:
-  scan_rtx_address (insn,  (x, 0),
-			base_reg_class (GET_MODE (x), MEM_ADDR_SPACE (x),
-	MEM, SCRATCH),
-			action, GET_MODE (x), MEM_ADDR_SPACE (x));
+  {
+	reg_class bclass = base_reg_class_for_rename (insn, GET_MODE (x),
+		  MEM_ADDR_SPACE (x),
+		  MEM, SCRATCH);
+
+	scan_rtx_address (insn,  (x, 0), bclass, action, GET_MODE (x),
+			  MEM_ADDR_SPACE (x));
+  }
   return;
 
 case SET: