Re: port-arm/49337: __popcountsi2() triggers illegal instruction

[Martin Husemann <martin%duskware.de@localhost>]

The following reply was made to PR port-arm/49337; it has been noted by GNATS.

From: Martin Husemann <martin%duskware.de@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: port-arm/49337: __popcountsi2() triggers illegal instruction
Date: Sat, 1 Nov 2014 23:03:19 +0100

 This is caused by the additional ld -x -r step during our build of libgcc
 object files.
 
 Not very helpfully objdump swaps them for display again, so the output
 is confusing and you need to double check with hexdump.
 
 How to reproduce:
 
 create a pop.S file:
 .global my__popcountsi2
 .hidden my__popcountsi2
         .text
 my__popcountsi2:
         ldr     r1, [pc, #52]
         mov     r2, #0
         ldr     ip, [pc, #48]
         mov     r3, r2
 
 and link it into a static binary, then use objdump -D to check:
 000103e8 <my__popcountsi2>:
    103e8:       e59f1034        ldr     r1, [pc, #52]   ; 10424 <my__popcountsi2+0x3c>
    103ec:       e3a02000        mov     r2, #0
    103f0:       e59fc030        ldr     ip, [pc, #48]   ; 10428 <my__popcountsi2+0x40>
    103f4:       e1a03002        mov     r3, r2
 
 Now create a ld -x -r variant of that .o file and link the result into a
 static binary, objdump -D again:
 
 000103e8 <my__popcountsi2>:
    103e8:       e59f1034        ldrcc   r9, [r0], #-4069        ; 0xfe5
    103ec:       e3a02000        eoreq   sl, r0, r3, ror #1
    103f0:       e59fc030        sbccc   r9, r0, r5, ror #31
    103f4:       e1a03002        eorseq  sl, r0, #225    ; 0xe1
 
 Martin