[GHC] #10383: AArch64: get GHC Calling convention working

[GHC]

#10383: AArch64: get GHC Calling convention working
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        Reporter:  erikd                |                   Owner:  erikd
            Type:  feature request      |                  Status:  new
        Priority:  normal               |               Milestone:  7.12.1
       Component:  Compiler             |                 Version:  7.11
      Resolution:                       |                Keywords:
Operating System:  Unknown/Multiple     |            Architecture:  aarch64
 Type of failure:  Building GHC failed  |               Test Case:
      Blocked By:                       |                Blocking:
 Related Tickets:                       |  Differential Revisions:
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Comment (by erikd):

 With the help of @rwbarton got the disassembly around the crash site:

 {{{
 (gdb) disass 0x0000007fb3dac244
 Dump of assembler code for function stg_ap_p_fast$def:
    0x0000007fb3dac1d8 <+0>:     mov     x24, x20
    0x0000007fb3dac1dc <+4>:     and     x8, x22, #0x7
    0x0000007fb3dac1e0 <+8>:     cmp     x8, #0x1
    0x0000007fb3dac1e4 <+12>:    b.ne    0x7fb3dac1f8
 <stg_ap_p_fast$def+32>
    0x0000007fb3dac1e8 <+16>:    ldr     x8, [x22,#-1]
    0x0000007fb3dac1ec <+20>:    mov     x20, x24
    0x0000007fb3dac1f0 <+24>:    blr     x8
    0x0000007fb3dac1f4 <+28>:    ret
    0x0000007fb3dac1f8 <+32>:    sub     x20, x24, #0x10
    0x0000007fb3dac1fc <+36>:    cmp     x20, x28
    0x0000007fb3dac200 <+40>:    b.cs    0x7fb3dac220
 <stg_ap_p_fast$def+72>
    0x0000007fb3dac204 <+44>:    str     x23, [x24,#-8]
    0x0000007fb3dac208 <+48>:    adrp    x8, 0x7fb3dc0000
    0x0000007fb3dac20c <+52>:    ldr     x8, [x8,#424]
    0x0000007fb3dac210 <+56>:    str     x8, [x24,#-16]!
    0x0000007fb3dac214 <+60>:    mov     x20, x24
    0x0000007fb3dac218 <+64>:    bl      0x7fb3da32a8
 <__stg_gc_enter_1$def>
    0x0000007fb3dac21c <+68>:    ret
    0x0000007fb3dac220 <+72>:    and     x22, x22, #0xfffffffffffffff8
    0x0000007fb3dac224 <+76>:    adrp    x25, 0x7fb3dbf000
    0x0000007fb3dac228 <+80>:    ldr     x25, [x25,#1584]
    0x0000007fb3dac22c <+84>:    ldr     x26, [x22]
    0x0000007fb3dac230 <+88>:    ldr     w8, [x25,#224]
    0x0000007fb3dac234 <+92>:    cbz     w8, 0x7fb3dac244
 <stg_ap_p_fast$def+108>
    0x0000007fb3dac238 <+96>:    adrp    x0, 0x7fb3dbe000 <cIL_str$def>
    0x0000007fb3dac23c <+100>:   add     x0, x0, #0x20
    0x0000007fb3dac240 <+104>:   bl      0x7fb3d7439c <debugBelch>
 => 0x0000007fb3dac244 <+108>:   ldrsw   x26, [x26,#-8]
    0x0000007fb3dac248 <+112>:   ldr     w8, [x25,#224]

 }}}

 which shows the crash on the instruction `ldrsw   x26, [x26,#-8]`:

 {{{
 (gdb) info registers
 x0             0x0      0
 x1             0x0      0
 x2             0x1      1
 x3             0x0      0
 x4             0x0      0
 x5             0x0      0
 x6             0xffffffbb       4294967227
 x7             0x0      0
 x8             0x40     64
 x9             0x0      0
 x10            0xffffffff       4294967295
 x11            0x1      1
 x12            0x7fb4591428     548486583336
 x13            0x12     18
 x14            0x7fb3a09fff     548474494975
 x15            0x2      2
 x16            0x7fb3dc0250     548478386768
 x17            0x7fb3c329f4     548476758516
 x18            0x7fffffa790     549755791248
 x19            0x7fb3dc4998     548478405016
 x20            0x7fb3a051c8     548474474952
 x21            0x7fb3a092b0     548474491568
 x22            0x7fb3dc4998     548478405016
 x23            0x7fb3a09291     548474491537
 x24            0x7fb3a051d8     548474474968
 x25            0x7fb3dc4578     548478403960
 x26            0x0      0
 x27            0x0      0
 x28            0x7fb3a050c0     548474474688
 x29            0x7fffffead0     549755808464
 x30            0x7fb3dac244     548478304836
 sp             0x7fffffaa30     0x7fffffaa30
 pc             0x7fb3dac244     0x7fb3dac244 <stg_ap_p_fast$def+108>
 cpsr           0x60000000       1610612736
 fpsr           0x0      0
 fpcr           0x0      0

 }}}

 and register `x26` is `0x0`.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10383#comment:9>
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