expand_expr has, for as long as I can remember, had the ability to
ignore the desired mode provided by its callers and instead returning
something in a completely different mode. It's always been the caller's
responsibility to deal with that.
For the testcase in 54041, we call expand_expr with a desired mode of
SImode, but it actually returns a HImode object. This causes the
assertion in convert_memory_address_addr_space to trip because the
passed mode must be the same as the mode of the memory address.
The fix is simple. If expand_expr returns something in the wrong mode,
convert it to the desired mode.
I've reviewed the resulting code for the m68k target and it looks
correct to me. I've also bootstrapped and regression tested on
x86_64-unknown-linux-gnu, though the new code most certainly does not
trigger there.
I guess if someone really wanted to be thorough, they'd test on a target
where pointers and integers are different sizes.
OK for the trunk?
Thanks,
Jeff
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2dbab72..4c7da83 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2014-02-05 Jeff Law <l...@redhat.com>
+
+ PR middle-end/54041
+ * expr.c (expand_expr_addr_1): Handle expand_expr returning an
+ object with an undesirable mode.
+
2014-02-05 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* config/rs6000/rs6000.c (altivec_expand_vec_perm_const): Change
diff --git a/gcc/expr.c b/gcc/expr.c
index 878a51b..9609c45 100644
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -7708,6 +7708,11 @@ expand_expr_addr_expr_1 (tree exp, rtx target, enum
machine_mode tmode,
modifier == EXPAND_INITIALIZER
? EXPAND_INITIALIZER : EXPAND_NORMAL);
+ /* expand_expr is allowed to return an object in a mode other
+ than TMODE. If it did, we need to convert. */
+ if (tmode != GET_MODE (tmp))
+ tmp = convert_modes (tmode, GET_MODE (tmp),
+ tmp, TYPE_UNSIGNED (TREE_TYPE (offset)));
result = convert_memory_address_addr_space (tmode, result, as);
tmp = convert_memory_address_addr_space (tmode, tmp, as);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index c81a00d..283912d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-02-05 Jeff Law <l...@redhat.com>
+
+ PR middle-end/54041
+ * gcc.target/m68k/pr54041.c: New test.
+
2014-02-05 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* gcc.dg/vmx/sum2s.c: New.
diff --git a/gcc/testsuite/gcc.target/m68k/pr54041.c
b/gcc/testsuite/gcc.target/m68k/pr54041.c
new file mode 100644
index 0000000..645cb6d
--- /dev/null
+++ b/gcc/testsuite/gcc.target/m68k/pr54041.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-O -mshort" } */
+
+extern int r[];
+
+int *fn(int i)
+{
+ return &r[i];
+}
+
