Compiling code that calls a function that returns a complex type with
-mrelax-pic-calls results in an ICE.
khazaddum$ cat tmp.c
__complex__ double cd;
__complex__ double foo (void) { return cd; }
void bar (void) { cd = foo (); }
khazaddum$ ./xgcc -B./ -mabicalls -G0 -mrelax-pic-calls -mexplicit-relocs -O -S
tmp.c
tmp.c: In function bar:
tmp.c:3:1: error: could not split insn
(call_insn/i 6 18 7 tmp.c:3 (parallel [
(set (reg:DF 32 $f0)
(call (mem:SI (reg/f:SI 25 $25 [195]) [0 S4 A32])
(unspec [
(const_int 16 [0x10])
(symbol_ref:SI ("foo") [flags 0x3] <function_decl
0xb74f4000 foo>)
] 55)))
(set (reg:DF 34 $f2)
(call (mem:SI (reg/f:SI 25 $25 [195]) [0 S4 A32])
(const_int 16 [0x10])))
(clobber (reg:SI 31 $31))
]) 574 {call_value_multiple_internal} (expr_list:REG_DEAD (reg/f:SI 25
$25 [195])
(expr_list:REG_EH_REGION (const_int 0 [0x0])
(nil)))
(expr_list:REG_DEP_TRUE (use (reg:SI 79 $fakec))
(nil)))
tmp.c:3:1: internal compiler error: in final_scan_insn, at final.c:2650
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.
I used a mipsisa32r2-sde-elf toolchain for this, configured without an
assembler. If you configure properly with an assembler, then it isn't
necessary to give the -mrelax-pic-calls and -mexplicit-relocs options. All you
need it -mabicalls and -G 0.
The problem is in mips_annotate_pic_calls. It looks for a CALL rtx, and then
modifies it. Unfortunately, a function returning complex has a call insn with
2 CALL rtx. Because only one was modified, we end up with unrecognizable RTL.
We either need to disable the optimization in this case, or extend it to work
with a call insn with more than one CALL rtx. The first one is easier, the
second one is preferable.
--
Summary: -mrelax-pic-calls fails with complex types
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: wilson at gcc dot gnu dot org
GCC target triplet: mips*-*-*
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43764
