Hello,
This patch plugs a GGC leak in gcse.c, which will hold on to test insn
to save memory. But this results in holding on to entire RTL function
bodies, the function's CFG, and a lot more.
Fix is simple: Clear the part of test_insn that causes this.
Bootstrapped&tested on powerpc64-unknown-linux-gnu.
OK for trunk?
Ciao!
Steven
* gcse.c (can_assign_to_reg_without_clobbers_p): Do not let pointers
from test_insn into GGC space escape via SET_SRC.
Index: gcse.c
===================================================================
--- gcse.c (revision 209530)
+++ gcse.c (working copy)
@@ -849,6 +849,7 @@ can_assign_to_reg_without_clobbers_p (rtx x)
{
int num_clobbers = 0;
int icode;
+ bool can_assign = false;
/* If this is a valid operand, we are OK. If it's VOIDmode, we aren't. */
if (general_operand (x, GET_MODE (x)))
@@ -866,6 +867,7 @@ can_assign_to_reg_without_clobbers_p (rtx x)
FIRST_PSEUDO_REGISTER * 2),
const0_rtx));
NEXT_INSN (test_insn) = PREV_INSN (test_insn) = 0;
+ INSN_LOCATION (test_insn) = UNKNOWN_LOCATION;
}
/* Now make an insn like the one we would make when GCSE'ing and see if
@@ -874,16 +876,19 @@ can_assign_to_reg_without_clobbers_p (rtx x)
SET_SRC (PATTERN (test_insn)) = x;
icode = recog (PATTERN (test_insn), test_insn, &num_clobbers);
- if (icode < 0)
- return false;
-
- if (num_clobbers > 0 && added_clobbers_hard_reg_p (icode))
- return false;
-
- if (targetm.cannot_copy_insn_p && targetm.cannot_copy_insn_p (test_insn))
- return false;
-
- return true;
+
+ /* If the test insn is valid and doesn't need clobbers, and the target also
+ has no objections, we're good. */
+ if (icode >= 0
+ && (num_clobbers == 0 || !added_clobbers_hard_reg_p (icode))
+ && ! (targetm.cannot_copy_insn_p
+ && targetm.cannot_copy_insn_p (test_insn)))
+ can_assign = true;
+
+ /* Make sure test_insn doesn't have any pointers into GC space. */
+ SET_SRC (PATTERN (test_insn)) = NULL_RTX;
+
+ return can_assign;
}
/* Return nonzero if the operands of expression X are unchanged from the
