[Committed] S/390: expand_tbegin remove jump over cc extraction

Andreas Krebbel krebbel@linux.vnet.ibm.com
Fri Jan 10 15:02:00 GMT 2014


Hi,

with the attached patch the jump over the extraction of CC into a GPR
for the good case (CC0) is removed.  Starting with tbegin being
flagged as "returns_twice" this generates slow code and prevents the
backend optimization for nonescaping transaction from working
correctly.

This fixes the following testsuite fails:

< FAIL: gcc.target/s390/htm-nofloat-2.c scan-assembler-not \\tstd\\t
< FAIL: gcc.target/s390/htm-nofloat-2.c scan-assembler-not \\tld\\t

Bootstrapped and regtested on s390 and s390x.

Committed to mainline and 4.8 branch.

Bye,

-Andreas-

2014-01-10  Andreas Krebbel  <Andreas.Krebbel@de.ibm.com>

	* config/s390/s390.c (s390_expand_tbegin): Remove jump over CC
	extraction in good case.

---
 gcc/config/s390/s390.c |   41 ++++++++----------------------------!!!!!
 1 file changed, 8 insertions(+), 28 deletions(-), 5 modifications(!)

Index: gcc/config/s390/s390.c
===================================================================
*** gcc/config/s390/s390.c.orig
--- gcc/config/s390/s390.c
*************** s390_gimplify_va_arg (tree valist, tree
*** 10005,10020 ****
  void
  s390_expand_tbegin (rtx dest, rtx tdb, rtx retry, bool clobber_fprs_p)
  {
-   const int CC0 = 1 << 3;
-   const int CC1 = 1 << 2;
-   const int CC3 = 1 << 0;
-   rtx abort_label = gen_label_rtx ();
-   rtx leave_label = gen_label_rtx ();
    rtx retry_plus_two = gen_reg_rtx (SImode);
    rtx retry_reg = gen_reg_rtx (SImode);
    rtx retry_label = NULL_RTX;
-   rtx jump;
-   int very_unlikely = REG_BR_PROB_BASE / 100 - 1;
  
    if (retry != NULL_RTX)
      {
--- 10005,10013 ----
*************** s390_expand_tbegin (rtx dest, rtx tdb, r
*** 10031,10068 ****
      emit_insn (gen_tbegin_nofloat_1 (gen_rtx_CONST_INT (VOIDmode, TBEGIN_MASK),
  				     tdb));
  
-   jump = s390_emit_jump (abort_label,
- 			 gen_rtx_NE (VOIDmode,
- 				     gen_rtx_REG (CCRAWmode, CC_REGNUM),
- 				     gen_rtx_CONST_INT (VOIDmode, CC0)));
- 
-   JUMP_LABEL (jump) = abort_label;
-   LABEL_NUSES (abort_label) = 1;
-   add_int_reg_note (jump, REG_BR_PROB, very_unlikely);
- 
-   /* Initialize CC return value.  */
-   emit_move_insn (dest, const0_rtx);
- 
-   s390_emit_jump (leave_label, NULL_RTX);
-   LABEL_NUSES (leave_label) = 1;
-   emit_barrier ();
- 
-   /* Abort handler code.  */
- 
-   emit_label (abort_label);
    emit_move_insn (dest, gen_rtx_UNSPEC (SImode,
  					gen_rtvec (1, gen_rtx_REG (CCRAWmode,
  								   CC_REGNUM)),
  					UNSPEC_CC_TO_INT));
    if (retry != NULL_RTX)
      {
        rtx count = gen_reg_rtx (SImode);
        jump = s390_emit_jump (leave_label,
  			     gen_rtx_EQ (VOIDmode,
  			       gen_rtx_REG (CCRAWmode, CC_REGNUM),
! 			       gen_rtx_CONST_INT (VOIDmode, CC1 | CC3)));
!       LABEL_NUSES (leave_label) = 2;
!       add_int_reg_note (jump, REG_BR_PROB, very_unlikely);
  
        /* CC2 - transient failure. Perform retry with ppa.  */
        emit_move_insn (count, retry_plus_two);
--- 10024,10048 ----
      emit_insn (gen_tbegin_nofloat_1 (gen_rtx_CONST_INT (VOIDmode, TBEGIN_MASK),
  				     tdb));
  
    emit_move_insn (dest, gen_rtx_UNSPEC (SImode,
  					gen_rtvec (1, gen_rtx_REG (CCRAWmode,
  								   CC_REGNUM)),
  					UNSPEC_CC_TO_INT));
    if (retry != NULL_RTX)
      {
+       const int CC0 = 1 << 3;
+       const int CC1 = 1 << 2;
+       const int CC3 = 1 << 0;
+       rtx jump;
        rtx count = gen_reg_rtx (SImode);
+       rtx leave_label = gen_label_rtx ();
+ 
+       /* Exit for success and permanent failures.  */
        jump = s390_emit_jump (leave_label,
  			     gen_rtx_EQ (VOIDmode,
  			       gen_rtx_REG (CCRAWmode, CC_REGNUM),
! 			       gen_rtx_CONST_INT (VOIDmode, CC0 | CC1 | CC3)));
!       LABEL_NUSES (leave_label) = 1;
  
        /* CC2 - transient failure. Perform retry with ppa.  */
        emit_move_insn (count, retry_plus_two);
*************** s390_expand_tbegin (rtx dest, rtx tdb, r
*** 10073,10081 ****
  					      retry_reg));
        JUMP_LABEL (jump) = retry_label;
        LABEL_NUSES (retry_label) = 1;
      }
- 
-   emit_label (leave_label);
  }
  
  /* Builtins.  */
--- 10053,10060 ----
  					      retry_reg));
        JUMP_LABEL (jump) = retry_label;
        LABEL_NUSES (retry_label) = 1;
+       emit_label (leave_label);
      }
  }
  
  /* Builtins.  */



More information about the Gcc-patches mailing list