Diff for /wikisrc/users/maya/vax-gcc.mdwn between versions 1.5 and 1.9

version 1.5, 2019/08/29 20:40:51 version 1.9, 2019/08/30 04:49:49
Line 1 Line 1
 # Various GCC/vax issues and invesigation #  # Various GCC/vax issues and invesigation #
   
   [WIP tree](gcc-mirror/)
   
 ## libgomp crash with -O2 ##  ## libgomp crash with -O2 ##
 Repro:  Repro:
   
Line 18  Repro: Line 20  Repro:
   
 Asserts at emit-rtl.c:2310 gcc_assert (memory_address_addr_space_p (mode, addr, as));  Asserts at emit-rtl.c:2310 gcc_assert (memory_address_addr_space_p (mode, addr, as));
   
 NetBSD avoids it with a [local diff](5f534f20bc66738c05c442a8f20088f55335b653/external/gpl3/gcc/dist/libgcc/gthr-posix.h#L418) to reload.c/dse.c.    NetBSD avoids it with a [local diff](https://github.com/NetBSD/src/commit/e437e96750193b86d0464965661f616e011056fa) to reload.c/dse.c.  
 It looks like a real bug in vax_legitimate_address_p not handling some addressing modes.    It looks like a real bug in vax_legitimate_address_p not handling some addressing modes.  
 The code to handle offset(reg)[index] might be off: it doesn't like if neither xfoo0, xfoo1 are constant.  The code to handle offset(reg)[index] might be off: it doesn't like if neither xfoo0, xfoo1 are constant.
   
Line 49  Repro: Line 51  Repro:
     EOF      EOF
     vax--netbsdelf-g++ -O2 -c decl.ii      vax--netbsdelf-g++ -O2 -c decl.ii
   
   This errors out with:
   
       $ env PATH=$PWD:$PATH ./xgcc -fno-use-linker-plugin -c -O2 ~/oacc/decl.ii -fno-tree-vectorize
       /home/fly/oacc/decl.ii: In function 'bool i()':
       /home/fly/oacc/decl.ii:17:1: error: unrecognizable insn:
          17 | }
             | ^
       (insn 13 12 14 2 (set (reg:SI 33)
               (subreg:SI (mem:DI (plus:SI (mult:SI (reg/v:SI 24 [ g ])
                               (const_int 8 [0x8]))
                           (reg/f:SI 23 [ _6 ])) [1 *_10+0 S8 A32]) 4)) "/home/fly/oacc/decl.ii":16:14 -1
            (nil))
       during RTL pass: vregs
       /home/fly/oacc/decl.ii:17:1: internal compiler error: in extract_insn, at recog.c:2310
       
   Providing a trivial scheduling will avoid subregs of mem.  
   However, this doesn't work for us. Our crash and mem subregs happen at a too early pass, most likely.
   
   ## DWARF ##
   
       flag_dwarf2_cfi_asm = 0;
   
   is kind of a big deal. We should probably get rid of it, but [binutils hates that.](https://github.com/NetBSD/src/commit/1df57dce3744cf4743358b098728a0658b80b8fb)
   
       ld: warning: dynamic relocation to `?' in readonly section `.eh_frame'
       ld: warning: dynamic relocation to `?' in readonly section `.eh_frame'
       ld: warning: creating a DT_TEXTREL in a shared object
       ld: .eh_frame_hdr refers to overlapping FDEs
       ld: final link failed: bad value
   
   ## review comments ##
   
   Jeff Law [provided some feedback](https://gcc.gnu.org/ml/gcc/2019-04/msg00281.html). More of it should be addressed.

Removed from v.1.5  
changed lines
  Added in v.1.9


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