Hi!
As can be seen on the testcase, this backend bug is still reproduceable even
on trunk, the backend just can't rely on cstoredi4 or cbranchdi4 expansion
not being performed with two constants, unless it has predicates that
disallow it (Steven's patch in the PR).
This patch just forces it into registers instead, it will be simplified by
RTL optimizers anyway later on (or another alternative is FAIL there in that
case, see my other patch in the PR).
I really don't care which way this is fixed, but having such ICE around for
so long when the fix is so easy is unnecessary.
Tested just on the testcase, given that previously we'd always ICE on it,
it can't make things worse.
Ok for trunk?
2013-01-21 Jakub Jelinek <ja...@redhat.com>
PR target/49069
* config/arm/arm.md (cbranchdi4, cstoredi4): Don't ICE if
both comparison operands are constants.
* gcc.dg/pr49069.c: New test.
--- gcc/config/arm/arm.md.jj 2013-01-11 09:03:13.000000000 +0100
+++ gcc/config/arm/arm.md 2013-01-17 16:57:58.246233079 +0100
@@ -7035,9 +7035,10 @@ (define_expand "cbranchdi4"
(pc)))]
"TARGET_32BIT"
"{
- /* We should not have two constants. */
- gcc_assert (GET_MODE (operands[1]) == DImode
- || GET_MODE (operands[2]) == DImode);
+ /* If we have two constants, force one into register. */
+ if (GET_MODE (operands[1]) != DImode
+ && GET_MODE (operands[2]) != DImode)
+ operands[1] = force_reg (DImode, operands[1]);
if (!arm_validize_comparison (&operands[0], &operands[1], &operands[2]))
FAIL;
@@ -7958,9 +7959,10 @@ (define_expand "cstoredi4"
(match_operand:DI 3 "cmpdi_operand" "")]))]
"TARGET_32BIT"
"{
- /* We should not have two constants. */
- gcc_assert (GET_MODE (operands[2]) == DImode
- || GET_MODE (operands[3]) == DImode);
+ /* If we have two constants, force one into register. */
+ if (GET_MODE (operands[2]) != DImode
+ && GET_MODE (operands[3]) != DImode)
+ operands[2] = force_reg (DImode, operands[2]);
if (!arm_validize_comparison (&operands[1],
&operands[2],
--- gcc/testsuite/gcc.dg/pr49069.c.jj 2012-11-17 15:43:17.572007394 +0100
+++ gcc/testsuite/gcc.dg/pr49069.c 2013-01-17 16:43:41.613146835 +0100
@@ -0,0 +1,15 @@
+/* PR target/49069 */
+/* { dg-do compile } */
+/* { dg-options "-Os -fno-tree-forwprop -Wno-div-by-zero" } */
+
+int a;
+const unsigned long long b[1] = { 1ULL };
+extern void bar (int);
+
+void
+foo (void)
+{
+ for (a = 0; a == 1; a = 2)
+ ;
+ bar (b[0] == (a == 0 ? a : a / 0));
+}
Jakub
