Scheduler patch for HARD_REGNO_CALL_PART_CLOBBERED

Scheduler patch for HARD_REGNO_CALL_PART_CLOBBERED

[Richard Sandiford]

If an instruction modifies the clobbered part of a partly
call-clobbered register, the scheduler might still move
that instruction across a call.

Patch tested on sh64-elf.  Fixes the attached test case
for -m5-32media.  OK to install?

Richard


	* sched-deps.c (sched_analyze): Check HARD_REGNO_CALL_PART_CLOBBERED.

Index: sched-deps.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/sched-deps.c,v
retrieving revision 1.48
diff -c -d -p -F^[(a-zA-Z0-9_^#] -r1.48 sched-deps.c
*** sched-deps.c	27 Sep 2002 01:07:52 -0000	1.48
--- sched-deps.c	18 Nov 2002 11:10:25 -0000
*************** sched_analyze (deps, head, tail)
*** 1287,1294 ****
  		    SET_REGNO_REG_SET (reg_pending_sets, i);
  		    SET_REGNO_REG_SET (reg_pending_uses, i);
  		  }
! 		/* Other call-clobbered hard regs may be clobbered.  */
! 		else if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
  		  SET_REGNO_REG_SET (reg_pending_clobbers, i);
  		/* We don't know what set of fixed registers might be used
  		   by the function, but it is certain that the stack pointer
--- 1287,1298 ----
  		    SET_REGNO_REG_SET (reg_pending_sets, i);
  		    SET_REGNO_REG_SET (reg_pending_uses, i);
  		  }
! 		/* Other call-clobbered hard regs may be clobbered.
! 		   Since we only have a choice between 'might be clobbered'
! 		   and 'definitely not clobbered', we must include all
! 		   partly call-clobbered registers here.  */
! 		else if (HARD_REGNO_CALL_PART_CLOBBERED (i, reg_raw_mode[i])
! 			 || TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
  		  SET_REGNO_REG_SET (reg_pending_clobbers, i);
  		/* We don't know what set of fixed registers might be used
  		   by the function, but it is certain that the stack pointer
*** /dev/null	Tue Nov 14 21:44:43 2000
--- testsuite/gcc.c-torture/execute/20021112-5.c	Fri Nov 15 16:39:39 2002
***************
*** 0 ****
--- 1,26 ----
+ /* Test whether a partly call-clobbered register will be moved over a call.
+    Although the original test case didn't use any GNUisms, it proved
+    difficult to reduce without the named register extension.  */
+ #if __SH64__ == 32
+ #define LOC asm ("r10")
+ #else
+ #define LOC
+ #endif
+ 
+ unsigned int foo (char *c, unsigned int x, unsigned int y)
+ {
+   register unsigned int z LOC;
+ 
+   sprintf (c, "%d", x / y);
+   z = x + 1;
+   return z / (y + 1);
+ }
+ 
+ int main ()
+ {
+   char c[16];
+ 
+   if (foo (c, ~1U, 4) != (~0U / 5))
+     abort ();
+   exit (0);
+ }

Re: Scheduler patch for HARD_REGNO_CALL_PART_CLOBBERED

[Richard Henderson]

On Mon, Nov 18, 2002 at 11:16:19AM +0000, Richard Sandiford wrote:
> 	* sched-deps.c (sched_analyze): Check HARD_REGNO_CALL_PART_CLOBBERED.

Ok.


r~