------- Comment #1 from amodra at bigpond dot net dot au 2008-06-27 01:52
-------
(insn 9 8 11 1 (set (reg/v/f:SI 119 [ p ])
(mem/u/c:SI (plus:SI (reg:SI 30 30)
(const:SI (minus:SI (symbol_ref/u:SI ("*.LC2") [flags 0x2])
(symbol_ref:SI ("*.LCTOC1"))))) [5 S4 A8])) -1 (nil)
(expr_list:REG_EQUAL (symbol_ref:SI ("myprint") [flags 0x1] <function_decl
0x40164300 myprint>)
(nil)))
[snip]
(call_insn 12 11 13 1 (parallel [
(call (mem:SI (reg/v/f:SI 119 [ p ]) [0 S4 A8])
(const_int 0 [0x0]))
(use (const_int 0 [0x0]))
(clobber (scratch:SI))
]) -1 (nil)
(nil)
(expr_list:REG_DEP_TRUE (use (reg:SI 3 3))
(nil)))
The first instruction is a GOT load of the function address, the second an
indirect call. No problem there. Indirect calls for -msecure-plt don't need
the GOT pointer to be valid.
The trouble occurrs when combine substitutes the first insn into the second to
get:
(call_insn 12 11 13 0 (parallel [
(call (mem:SI (symbol_ref:SI ("myprint") [flags 0x1] <function_decl
0x40164300 myprint>) [0 S4 A8])
(const_int 0 [0x0]))
(use (const_int 0 [0x0]))
(clobber (scratch:SI))
]) 402 {*call_nonlocal_sysv} (insn_list:REG_DEP_TRUE 11 (nil))
(expr_list:REG_UNUSED (scratch:SI)
(expr_list:REG_DEAD (reg:SI 3 3)
(nil)))
(expr_list:REG_DEP_TRUE (use (reg:SI 3 3))
(nil)))
Note that lack of anything marking r30 as used.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36634
