This patch fixes pr60556, a GCC ICE. The problem is in convert_move where,
if we are trying to put a 32 bit address into a 64 bit destination we
can wind up calling emit_move_insn with NULL_RTX as a source.
The problem comes when creating fill_value. If unsignedp is false
then we call emit_store_flag to set fill_value. If lowfrom is a symbol
reference then emit_store_flag returns NULL_RTX (because symbol references
are constant) and we wind up calling emit_move_insn with NULL_RTX as a
source and getting an ICE.
My fix is to check for a symbol reference up where we are already
checking for memory references and force the symbol into a register
before calling emit_store_flag. This will prevent emit_store_flag
from returning NULL_RTX. In theory we could force the symbol
reference into a register only if unsignedp is false, but I think
it is cleaner to always put the symbol reference into a register.
Tested on mips-mti-linux-gnu with no regressions.
OK for checkin?
Steve Ellcey
sell...@mips.com
2014-03-20 Steve Ellcey <sell...@mips.com>
PR middle-end/60556
* expr.c (convert_move): Force symbol references into register.
diff --git a/gcc/expr.c b/gcc/expr.c
index be62c53..d065588 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -533,7 +533,8 @@ convert_move (rtx to, rtx from, int unsignedp)
conversion sequence might require several references to it and we
must ensure we're getting the same value every time. */
- if (MEM_P (from) || reg_overlap_mentioned_p (to, from))
+ if (MEM_P (from) || GET_CODE (from) == SYMBOL_REF
+ || reg_overlap_mentioned_p (to, from))
from = force_reg (from_mode, from);
/* Get a copy of FROM widened to a word, if necessary. */
2014-03-20 Steve Ellcey <sell...@mips.com>
PR middle-end/60556
gcc.dg/pr60556.c: New.
diff --git a/gcc/testsuite/gcc.dg/pr60556.c b/gcc/testsuite/gcc.dg/pr60556.c
new file mode 100644
index 0000000..3b5bbe5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr60556.c
@@ -0,0 +1,7 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int g (int);
+unsigned long long f(void) {
+ return (unsigned long long)(long)&g;
+}
