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authorRichard Sandiford <richard@codesourcery.com>2007-06-30 12:23:18 +0000
committerRichard Sandiford <rsandifo@gcc.gnu.org>2007-06-30 12:23:18 +0000
commita4fbe84bd2ae7c5cacbada14abe4d3b9a7bbe6d0 (patch)
treec8758fc6c93ba74b915a04708fec331c7154a6d6 /gcc/dce.c
parent9d35384d74fb0f8b0f8a25b6d44342d5991455ee (diff)
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revert: dce.c (deletable_insn_p_1): New function, split out from...
gcc/ Revert: 2007-06-27 Richard Sandiford <richard@codesourcery.com> * dce.c (deletable_insn_p_1): New function, split out from... (deletable_insn_p): ...here. Only treat bare USEs and CLOBBERs specially, not those inside PARALLELs. Remove BODY argument and adjust recursive call accordingly. (prescan_insns_for_dce): Update call to delete_insn_p. From-SVN: r126143
Diffstat (limited to 'gcc/dce.c')
-rw-r--r--gcc/dce.c64
1 files changed, 24 insertions, 40 deletions
diff --git a/gcc/dce.c b/gcc/dce.c
index 2e8b77a..0252d4d 100644
--- a/gcc/dce.c
+++ b/gcc/dce.c
@@ -58,15 +58,16 @@ static bitmap_obstack dce_tmp_bitmap_obstack;
static sbitmap marked = NULL;
-/* A subroutine for which BODY is part of the instruction being tested;
- either the top-level pattern, or an element of a PARALLEL. The
- instruction is known not to be a bare USE or CLOBBER. */
+/* Return true if INSN with BODY is a normal instruction that can be
+ deleted by the DCE pass. */
static bool
-deletable_insn_p_1 (rtx body)
+deletable_insn_p (rtx insn, rtx body, bool fast)
{
+ rtx x;
switch (GET_CODE (body))
{
+ case USE:
case PREFETCH:
case TRAP_IF:
/* The UNSPEC case was added here because the ia-64 claims that
@@ -78,35 +79,6 @@ deletable_insn_p_1 (rtx body)
case UNSPEC:
return false;
- default:
- if (volatile_insn_p (body))
- return false;
-
- if (flag_non_call_exceptions && may_trap_p (body))
- return false;
-
- return true;
- }
-}
-
-/* Return true if INSN is a normal instruction that can be deleted by
- the DCE pass. */
-
-static bool
-deletable_insn_p (rtx insn, bool fast)
-{
- rtx body, x;
- int i;
-
- if (!NONJUMP_INSN_P (insn))
- return false;
-
- body = PATTERN (insn);
- switch (GET_CODE (body))
- {
- case USE:
- return false;
-
case CLOBBER:
if (fast)
{
@@ -116,20 +88,32 @@ deletable_insn_p (rtx insn, bool fast)
x = XEXP (body, 0);
return REG_P (x) && (!HARD_REGISTER_P (x) || reload_completed);
}
- else
+ else
/* Because of the way that use-def chains are built, it is not
possible to tell if the clobber is dead because it can
never be the target of a use-def chain. */
return false;
case PARALLEL:
- for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
- if (!deletable_insn_p_1 (XVECEXP (body, 0, i)))
- return false;
- return true;
+ {
+ int i;
+ for (i = XVECLEN (body, 0) - 1; i >= 0; i--)
+ if (!deletable_insn_p (insn, XVECEXP (body, 0, i), fast))
+ return false;
+ return true;
+ }
default:
- return deletable_insn_p_1 (body);
+ if (!NONJUMP_INSN_P (insn))
+ return false;
+
+ if (volatile_insn_p (body))
+ return false;
+
+ if (flag_non_call_exceptions && may_trap_p (body))
+ return false;
+
+ return true;
}
}
@@ -385,7 +369,7 @@ prescan_insns_for_dce (bool fast)
rtx note = find_reg_note (insn, REG_LIBCALL_ID, NULL_RTX);
if (note)
mark_libcall (insn, fast);
- else if (deletable_insn_p (insn, fast))
+ else if (deletable_insn_p (insn, PATTERN (insn), fast))
mark_nonreg_stores (PATTERN (insn), insn, fast);
else
mark_insn (insn, fast);