Some of the maths builtins can expand to a call followed by a bit
of postprocessing. With 4.8's PARALLEL return optimisations, these
embedded calls might return a PARALLEL of pseudos, but the postprocessing
isn't prepared to deal with that. This leads to an ICE in builtins-53.c
on n32 and n64 mips64-linux-gnu.
One fix might have been to pass an explicit register target to the
expand routines, but that target's only a hint. This patch instead
adds an avoid_group_rtx function (named after gen_group_rtx) to convert
PARALLELs to pseudos where necessary.
I wondered whether it was really safe for expand_builtin_int_roundingfn_2
to pass "target == const0_rtx" as the "ignore" parameter to expand_call,
given that we don't actually ignore the return value ourselves
(even if the caller does). I suppose it is safe though,
since expand_call will always return const0_rtx in that case,
and this code is dealing with integer return values.
Tested on mips64-linux-gnu. OK to install? Or is there a better way?
Richard
gcc/
* expr.h (avoid_group_rtx): Declare.
* expr.c (avoid_group_rtx): New function.
* builtins.c (expand_builtin_int_roundingfn): Call it.
(expand_builtin_int_roundingfn_2): Likewise.
Index: gcc/expr.h
===================================================================
--- gcc/expr.h 2012-12-23 09:21:21.969086853 +0000
+++ gcc/expr.h 2012-12-23 09:32:03.487440220 +0000
@@ -334,6 +334,8 @@ extern rtx emit_group_move_into_temps (r
PARALLEL. */
extern void emit_group_store (rtx, rtx, tree, int);
+extern rtx avoid_group_rtx (rtx, tree);
+
/* Copy BLKmode object from a set of registers. */
extern void copy_blkmode_from_reg (rtx, rtx, tree);
Index: gcc/expr.c
===================================================================
--- gcc/expr.c 2012-12-23 09:21:21.980086911 +0000
+++ gcc/expr.c 2012-12-23 09:32:03.485440208 +0000
@@ -2079,6 +2079,23 @@ emit_group_store (rtx orig_dst, rtx src,
emit_move_insn (orig_dst, dst);
}
+/* Return a form of X that does not use a PARALLEL. TYPE is the type
+ of the value stored in X. */
+
+rtx
+avoid_group_rtx (rtx x, tree type)
+{
+ enum machine_mode mode = TYPE_MODE (type);
+ gcc_checking_assert (GET_MODE (x) == VOIDmode || GET_MODE (x) == mode);
+ if (GET_CODE (x) == PARALLEL)
+ {
+ rtx result = gen_reg_rtx (mode);
+ emit_group_store (result, x, type, int_size_in_bytes (type));
+ return result;
+ }
+ return x;
+}
+
/* Copy a BLKmode object of TYPE out of a register SRCREG into TARGET.
This is used on targets that return BLKmode values in registers. */
Index: gcc/builtins.c
===================================================================
--- gcc/builtins.c 2012-12-23 09:21:21.981086916 +0000
+++ gcc/builtins.c 2012-12-23 09:34:47.813323158 +0000
@@ -2757,6 +2757,7 @@ expand_builtin_int_roundingfn (tree exp,
exp = build_call_nofold_loc (EXPR_LOCATION (exp), fallback_fndecl, 1, arg);
tmp = expand_normal (exp);
+ tmp = avoid_group_rtx (tmp, TREE_TYPE (exp));
/* Truncate the result of floating point optab to integer
via expand_fix (). */
@@ -2860,6 +2861,7 @@ expand_builtin_int_roundingfn_2 (tree ex
fallback_fndecl, 1, arg);
target = expand_call (exp, NULL_RTX, target == const0_rtx);
+ target = avoid_group_rtx (target, TREE_TYPE (exp));
return convert_to_mode (mode, target, 0);
}
