re PR rtl-optimization/55122 (ICE: maximum number of LRA constraint passes is achieve...

2012-11-07  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/55122
	* lra-constraints.c (match_reload): Sync values for dead input
	pseudos.

2012-11-07  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/55122
	* gcc.dg/pr55122.c: New test.

From-SVN: r193310

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 24d9845..294b3a5 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2012-11-07  Vladimir Makarov  <vmakarov@redhat.com>
+
+       PR rtl-optimization/55122
+       * lra-constraints.c (match_reload): Sync values for dead input
+       pseudos.
+
 2012-11-07  Richard Henderson  <rth@redhat.com>
 
        * trans-mem.c (pass_ipa_tm): Don't use TODO_update_ssa.

diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index ae8b834..bcba590 100644 (file)
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -682,6 +682,11 @@ match_reload (signed char out, signed char *ins, enum reg_class goal_class,
            new_out_reg = gen_lowpart_SUBREG (outmode, reg);
          else
            new_out_reg = gen_rtx_SUBREG (outmode, reg, 0);
+         /* If the input reg is dying here, we can use the same hard
+            register for REG and IN_RTX.  */
+         if (REG_P (in_rtx)
+             && find_regno_note (curr_insn, REG_DEAD, REGNO (in_rtx)))
+           lra_reg_info[REGNO (reg)].val = lra_reg_info[REGNO (in_rtx)].val;
        }
       else
        {
@@ -698,6 +703,19 @@ match_reload (signed char out, signed char *ins, enum reg_class goal_class,
             it at the end of LRA work.  */
          clobber = emit_clobber (new_out_reg);
          LRA_TEMP_CLOBBER_P (PATTERN (clobber)) = 1;
+         if (GET_CODE (in_rtx) == SUBREG)
+           {
+             rtx subreg_reg = SUBREG_REG (in_rtx);
+             
+             /* If SUBREG_REG is dying here and sub-registers IN_RTX
+                and NEW_IN_REG are similar, we can use the same hard
+                register for REG and SUBREG_REG.  */
+             if (REG_P (subreg_reg) && GET_MODE (subreg_reg) == outmode
+                 && SUBREG_BYTE (in_rtx) == SUBREG_BYTE (new_in_reg)
+                 && find_regno_note (curr_insn, REG_DEAD, REGNO (subreg_reg)))
+               lra_reg_info[REGNO (reg)].val
+                 = lra_reg_info[REGNO (subreg_reg)].val;
+           }
        }
     }
   else

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4ff6ff5..6ceec1f 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-11-07  Vladimir Makarov  <vmakarov@redhat.com>
+
+       PR rtl-optimization/55122
+       * gcc.dg/pr55122.c: New test.
+
 2012-11-07  David Edelsohn  <dje.gcc@gmail.com>
 
        * gcc.target/powerpc/pr46728-[1234578].c: Tighten regex to ignore

diff --git a/gcc/testsuite/gcc.dg/pr55122.c b/gcc/testsuite/gcc.dg/pr55122.c
new file mode 100644 (file)
index 0000000..a290ae0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr55122.c
@@ -0,0 +1,14 @@
+/* PR rtl-optimization/55122 */
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+int i, a;
+unsigned long long b;
+
+void f(void)
+{
+    for(i = 0; i < 15; i++)
+        b *= b;
+
+    b *= a ? 0 : b;
+}