rms@AI.MIT.EDU (05/23/89)
Return-Path: <mcgrath%tully.Berkeley.EDU@ginger.berkeley.edu> To: bug-gcc@prep.ai.mit.edu Subject: gas 1.33 (68k) produces bad code Date: Mon, 22 May 89 21:51:23 PDT From: Roland McGrath <mcgrath%tully.Berkeley.EDU@ginger.berkeley.edu> GAS 1.33, compiled out of the box for 68k (unpack distribution; make a68) on a Sun 3 (68020), Sun Unix 3.5. With the input: #NO_APP gcc_compiled.: .text .even .globl _func _func: link a6,#0 unlk a6 rts .even .globl _foo _foo: link a6,#0 movel _idx,d0 movel _list,a0 movel a0@(d0:l:4),sp@- jbsr _func unlk a6 rts .globl _idx .data .even _idx: .long 0 .globl _list .text .even _list: .long 0 .even .globl _main _main: link a6,#0 jbsr _foo unlk a6 rts The code produced by Sun as for the `foo' function (disassembly by GDB 3.1.1): 0x20a8 <foo>: linkw fp,#0 0x20ac <foo+4>: movel @#0x20004 <idx>,d0 0x20b2 <foo+10>: moveal 0x20c4 <list>,a0 0x20b6 <foo+14>: movel 0(a0)[d0.l*4],-(sp) 0x20ba <foo+18>: jsr @#0x20a0 <func> 0x20c0 <foo+24>: unlk fp 0x20c2 <foo+26>: rts The code produced by GAS: 0x20a8 <foo>: linkw fp,#0 0x20ac <foo+4>: movel @#0x20034 <idx>,d0 0x20b2 <foo+10>: moveal @#0x20c2 <list>,a0 0x20b8 <foo+16>: movel 0(a0)[d0.l*4],-(sp) 0x20bc <foo+20>: bsr 0x20a0 <func> 0x20be <foo+22>: unlk fp 0x20c0 <foo+24>: rts (For some reason the addresses of `idx' and `list' are different, but ignore that.) The bad code is at 0x20b2 <foo+10>. Sun assembles: movel _list,a0 (which is what the source is). GAS assembles: movel @_list, a0