http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49007
--- Comment #13 from John David Anglin <danglin at gcc dot gnu.org> 2011-05-23
15:48:43 UTC ---
Ok, I'll see if I can find out why it's being deleted. In the first try,
we have the following rtl:
Breakpoint 12, mark_target_live_regs (insns=0x1b8a020, target=0x1b98f90,
res=0xbfffeda0) at ../../gcc/gcc/resource.c:975
975 for (insn = start_insn; insn != stop_insn;
(gdb) p debug_rtx_list (start_insn, 12)
(code_label 322 386 91 16 617 "" [1 uses])
(note 91 322 433 [bb 16] NOTE_INSN_BASIC_BLOCK)
(insn 433 91 64 (use (insn/s 92 59 366 (set (reg/v:SI 4 %r4 [orig:111 i ]
[111])
(const_int 2 [0x2])) 37 {*pa.md:2542} (expr_list:REG_EQUAL
(const_int 2 [0x2])
(nil)))) -1 (nil))
(insn 64 433 65 ../../gcc/gcc/tree-cfgcleanup.c:697 (set (reg/f:SI 1 %r1 [216])
(high:SI (symbol_ref:SI ("cfun") [flags 0x240] <var_decl 0xc204e0
cfun>))) 49 {*pa.md:3017} (expr_list:REG_EQUIV (high:SI (symbol_ref:SI ("cfun")
[flags 0x240] <var_decl 0xc204e0 cfun>))
(nil)))
(insn 65 64 94 ../../gcc/gcc/tree-cfgcleanup.c:697 (set (reg/f:SI 3 %r3 [217])
(lo_sum:SI (reg/f:SI 1 %r1 [216])
(symbol_ref:SI ("cfun") [flags 0x240] <var_decl 0xc204e0 cfun>)))
52 {*pa.md:3097} (expr_list:REG_DEAD (reg/f:SI 1 %r1 [216])
(nil)))
(note 94 65 95 [bb 17] NOTE_INSN_BASIC_BLOCK)
(insn 95 94 435 ../../gcc/gcc/basic-block.h:194 (set (reg:SI 28 %r28 [143])
(plus:SI (reg/v:SI 4 %r4 [orig:111 i ] [111])
(const_int 2 [0x2]))) 111 {addsi3} (nil))
(code_label 435 95 96 620 "" [1 uses])
(insn 96 435 97 ../../gcc/gcc/basic-block.h:194 (set (reg/v/f:SI 26 %r26
[orig:110 bb ] [110])
(mem/s/f/j:SI (plus:SI (mult:SI (reg:SI 28 %r28 [143])
(const_int 4 [0x4]))
(reg/f:SI 26 %r26 [orig:104 iftmp.1903 ] [104])) [0
<variable>.vec S4 A32])) 37 {*pa.md:2542} (expr_list:REG_DEAD (reg:SI 28 %r28
[143])
(nil)))
(jump_insn 97 96 98 ../../gcc/gcc/tree-cfgcleanup.c:698 (set (pc)
(if_then_else (eq (reg/v/f:SI 26 %r26 [orig:110 bb ] [110])
(const_int 0 [0x0]))
(label_ref 105)
(pc))) 25 {*pa.md:1770} (expr_list:REG_BR_PROB (const_int 2820
[0xb04])
(nil)))
(note 98 97 100 [bb 18] NOTE_INSN_BASIC_BLOCK)
(call_insn 100 98 101 ../../gcc/gcc/tree-cfgcleanup.c:699 (parallel [
(set (reg:SI 28 %r28)
(call (mem:SI (symbol_ref/v:SI ("@cleanup_tree_cfg_bb") [flags
0x203] <function_decl 0x1564850 cleanup_tree_cfg_bb>) [0 S4 A32])
(const_int 16 [0x10])))
(clobber (reg:SI 1 %r1))
(clobber (reg:SI 2 %r2))
(use (const_int 0 [0x0]))
]) 212 {call_val_symref} (expr_list:REG_DEAD (reg:SI 26 %r26)
(expr_list:REG_EH_REGION (const_int 0 [0x0])
(nil)))
(expr_list:REG_DEP_TRUE (use (reg:SI 26 %r26))
(nil)))
As can be seen, insn 64 is subsequently replaced by a use. Maybe this causes
the deletion of insn 433.
433 to be deleted
