asm::delay with inline-asm feature is broken on latest nightly

[Piroro-hs]

asm::delay hangs up on rustc 1.49.0-nightly (8dae8cdcc 2020-10-12). Target is thumbv7em-none-eabihf.

The compiler produces following binary. It looks like the operand of subs is screwed up.

objdump

0800023c <_ZN8cortex_m3asm5delay17h6801139b6c4b4672E>:
 800023c: 80 b5         push    {r7, lr}
 800023e: 6f 46         mov     r7, sp
 8000240: 84 b0         sub     sp, #16
 8000242: 03 90         str     r0, [sp, #12]
 8000244: 01 21         movs    r1, #1
 8000246: 01 eb 90 00   add.w   r0, r1, r0, lsr #2
 800024a: 00 21         movs    r1, #0
 800024c: 00 29         cmp     r1, #0
 800024e: 01 90         str     r0, [sp, #4]
 8000250: 09 d1         bne     #18 <_ZN8cortex_m3asm5delay17h6801139b6c4b4672E+0x2e>
 8000252: ff e7         b       #-2 <_ZN8cortex_m3asm5delay17h6801139b6c4b4672E+0x1c>
 8000254: 01 98         ldr     r0, [sp, #4]
 8000256: 02 90         str     r0, [sp, #8]
 8000258: 02 99         ldr     r1, [sp, #8]

 800025a: 00 bf         nop
 800025c: b1 39         subs    r1, #177 <---- !?
 800025e: fc d1         bne     #-8 <_ZN8cortex_m3asm5delay17h6801139b6c4b4672E+0x22>

 8000260: 02 91         str     r1, [sp, #8]
 8000262: 04 b0         add     sp, #16
 8000264: 80 bd         pop     {r7, pc}
 8000266: 41 f2 b0 30   movw    r0, #5040
 800026a: c0 f6 00 00   movt    r0, #2048
 800026e: 41 f2 94 32   movw    r2, #5012
 8000272: c0 f6 00 02   movt    r2, #2048
 8000276: 1c 21         movs    r1, #28
 8000278: 00 f0 1f fd   bl      #2622
 800027c: fe de         trap

Please publish v0.6.4 (or 0.7?) with #262 included, if possible.

[adamgreig]

This should now by fixed by the new release of cortex-m 0.6.4, thanks for reporting!