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[PATCH] Fix var-tracking ICEs due to i?86 delegitimization bug (PR target/47201)
- From: Jakub Jelinek <jakub at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Fri, 7 Jan 2011 15:59:42 +0100
- Subject: [PATCH] Fix var-tracking ICEs due to i?86 delegitimization bug (PR target/47201)
- Reply-to: Jakub Jelinek <jakub at redhat dot com>
Hi!
delegitimize_address hook should never return NULL, it should either
return a simplified rtx, or the original one. But when simplify_gen_subreg
is called, it can fail on questionable code like the attached one, where
it was mem:SF of a GOTPCREL address, which ought to be
simplified into lowpart SFmode subreg of DImode symbol_ref, but target
doesn't allow that. For var-tracking/debuginfo purposes we actually
can handle any subregs, but delegitimization hook is used in other places
too.
So fixed by returning the original x if simplification failed.
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2011-01-07 Jakub Jelinek <jakub@redhat.com>
PR target/47201
* config/i386/i386.c (ix86_delegitimize_address): If
simplify_gen_subreg fails, return orig_x.
* gcc.dg/pr47201.c: New test.
--- gcc/config/i386/i386.c.jj 2011-01-06 10:21:47.000000000 +0100
+++ gcc/config/i386/i386.c 2011-01-07 09:50:23.000000000 +0100
@@ -13154,7 +13154,11 @@ ix86_delegitimize_address (rtx x)
return ix86_delegitimize_tls_address (orig_x);
x = XVECEXP (XEXP (x, 0), 0, 0);
if (GET_MODE (orig_x) != Pmode)
- return simplify_gen_subreg (GET_MODE (orig_x), x, Pmode, 0);
+ {
+ x = simplify_gen_subreg (GET_MODE (orig_x), x, Pmode, 0);
+ if (x == NULL_RTX)
+ return orig_x;
+ }
return x;
}
@@ -13223,7 +13227,11 @@ ix86_delegitimize_address (rtx x)
return orig_x;
}
if (GET_MODE (orig_x) != Pmode && MEM_P (orig_x))
- return simplify_gen_subreg (GET_MODE (orig_x), result, Pmode, 0);
+ {
+ result = simplify_gen_subreg (GET_MODE (orig_x), result, Pmode, 0);
+ if (result == NULL_RTX)
+ return orig_x;
+ }
return result;
}
--- gcc/testsuite/gcc.dg/pr47201.c.jj 2011-01-07 09:57:46.000000000 +0100
+++ gcc/testsuite/gcc.dg/pr47201.c 2011-01-07 09:57:37.000000000 +0100
@@ -0,0 +1,18 @@
+/* PR target/47201 */
+/* { dg-do compile } */
+/* { dg-options "-O -fpic -g" { target fpic } } */
+
+union U
+{
+ __UINTPTR_TYPE__ m;
+ float d;
+} u;
+
+int
+foo (void)
+{
+ union U v = {
+ (__UINTPTR_TYPE__)&u
+ };
+ return u.d == v.d;
+}
Jakub