From patchwork Mon Jul 19 09:54:58 2010
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Subject: Emit more REG_EQUIV notes for function args (PR42235)
Date: Sun, 18 Jul 2010 23:54:58 -0000
From: Bernd Schmidt <bernds@codesourcery.com>
X-Patchwork-Id: 59185
Message-Id: <4C4420F2.5010807@codesourcery.com>
To: Jeff Law <law@redhat.com>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>,
 John David Anglin <dave@hiauly1.hia.nrc.ca>

On 07/15/2010 07:13 PM, Bernd Schmidt wrote:
> On 07/15/2010 12:28 AM, Jeff Law wrote:
>> On 07/14/10 15:30, Bernd Schmidt wrote:
>>> If necessary I can try to test for a single insn with single_set and
>>> push it to the sequence otherwise.
>>>    
>> For the mn103, the conversions were single insns...
>>
>> Ultimately,  I think you have to peek at the insn(s) and see what
>> registers they set/clobber.
> 
> How's this?  Bootstrapped and tested on i686-linux.  ARM tests in progress.

This seems to have caused a bootstrap failure on hppa.  A QImode value
is passed in a SImode reg and then should get extended to DImode; we
must make sure we use a qidi extension.  The following patch does that;
I've not heard back whether it fixes the hppa bootstrap, but it seems to
work on arm-linux (one extra testsuite failure caused by an unrelated
change in the same tree).  Also bootstrapped on i686-linux.  Ok?


Bernd
* function.c (assign_parm_setup_reg): Use nominal_mode as the
	source mode for extensions.


Index: function.c
===================================================================
--- function.c	(revision 162277)
+++ function.c	(working copy)
@@ -2940,18 +2940,18 @@ assign_parm_setup_reg (struct assign_par
 	 First, we try to emit an insn which performs the necessary
 	 conversion.  We verify that this insn does not clobber any
 	 hard registers.  */
-
+      enum machine_mode entry_mode = data->nominal_mode;
       enum insn_code icode;
       rtx op0, op1;
 
-      icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
+      icode = can_extend_p (promoted_nominal_mode, entry_mode,
 			    unsignedp);
 
       op0 = parmreg;
       op1 = validated_mem;
       if (icode != CODE_FOR_nothing
 	  && insn_data[icode].operand[0].predicate (op0, promoted_nominal_mode)
-	  && insn_data[icode].operand[1].predicate (op1, data->passed_mode))
+	  && insn_data[icode].operand[1].predicate (op1, entry_mode))
 	{
 	  enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
 	  rtx insn, insns;
@@ -2959,7 +2959,7 @@ assign_parm_setup_reg (struct assign_par
 
 	  start_sequence ();
 	  insn = gen_extend_insn (op0, op1, promoted_nominal_mode,
-				  data->passed_mode, unsignedp);
+				  entry_mode, unsignedp);
 	  emit_insn (insn);
 	  insns = get_insns ();