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Cortex M3 compiler optimization producing incorrect disassembled code

Note: This was originally posted on 20th May 2009 at http://forums.arm.com

I am seeing that Cortex M3 compiler is producing incorrect disassembled code.
I am using ARM RVCT 3.0 Build 440

    myMain
    $t
    .ROM_SECTION
        0x00000040:    e92d5ff0    -.._    PUSH     {r4-r12,lr}
        0x00000044:    491d        .I      LDR      r1,[pc,#116]  ; [0xbc] = 0x42700
        0x00000046:    4f1d        .O      LDR      r7,[pc,#116]  ; [0xbc] = 0x42700
        0x00000048:    780a        .x      LDRB     r2,[r1,#0]
        0x0000004a:    7849        Ix      LDRB     r1,[r1,#1]
        0x0000004c:    f8dfb070    ..p.    LDR      r11,[pc,#112]  ; [0xc0] = 0x20001a2c
        0x00000050:    2000        .       MOVS     r0,#0
        0x00000052:    2404        .$      MOVS     r4,#4
        0x00000054:    1d3f        ?.      ADDS     r7,r7,#4
        0x00000056:    f04f080f    O...    MOV      r8,#0xf
        0x0000005a:    f1ab0a04    ....    SUB      r10,r11,#4
        0x0000005e:    428a        .B      CMP      r2,r1
        0x00000060:    d311        ..      BCC      0x86  ; myMain + 70
        0x00000062:    4680        .F      MOV      r8,r0
        0x00000064:    e018        ..      B        0x98  ; myMain + 88
        0x00000066:    2104        .!      MOVS     r1,#4
        0x00000068:    f8d76250    ..Pb    LDR      r6,[r7,#0x250]
        0x0000006c:    462b        +F      MOV      r3,r5
        0x0000006e:    4652        RF      MOV      r2,r10
        0x00000070:    200d        .       MOVS     r0,#0xd
        0x00000072:    47b0        .G      BLX      r6
        0x00000074:    2104        .!      MOVS     r1,#4
        0x00000076:    f8d76250    ..Pb    LDR      r6,[r7,#0x250]
        0x0000007a:    462b        +F      MOV      r3,r5
        0x0000007c:    465a        ZF      MOV      r2,r11
        0x0000007e:    2018        .       MOVS     r0,#0x18
        0x00000080:    47b0        .G      BLX      r6
        0x00000082:    1e64        d.      SUBS     r4,r4,#1
        0x00000084:    e003        ..      B        0x8e  ; myMain + 78
        0x00000086:    eba80900    ....    SUB      r9,r8,r0
        0x0000008a:    eb000559    ..Y.    ADD      r5,r0,r9,LSR #1
        0x0000008e:    f1b90f01    ....    CMP      r9,#1
        0x00000092:    d001        ..      BEQ      0x98  ; myMain + 88
        0x00000094:    2c00        .,      CMP      r4,#0
        0x00000096:    d1e6        ..      BNE      0x66  ; myMain + 38
        0x00000098:    2104        .!      MOVS     r1,#4
        0x0000009a:    f8d74250    ..PB    LDR      r4,[r7,#0x250]
        0x0000009e:    4643        CF      MOV      r3,r8
        0x000000a0:    4652        RF      MOV      r2,r10
        0x000000a2:    200d        .       MOVS     r0,#0xd
        0x000000a4:    47a0        .G      BLX      r4
        0x000000a6:    f8d74250    ..PB    LDR      r4,[r7,#0x250]
        0x000000aa:    4643        CF      MOV      r3,r8
        0x000000ac:    465a        ZF      MOV      r2,r11
        0x000000ae:    46a4        .F      MOV      r12,r4
        0x000000b0:    e8bd5ff0    ..._    POP      {r4-r12,lr}
        0x000000b4:    2104        .!      MOVS     r1,#4
        0x000000b6:    2018        .       MOVS     r0,#0x18
        0x000000b8:    4760        `G      BX       r12
    $d
        0x000000ba:    0000        ..      DCW    0
        0x000000bc:    00042700    .'..    DCD    272128
        0x000000c0:    20001a2c    ,..     DCD    536877612

See the lst file especially the following two places

        0x0000009a:    f8d74250    ..PB    LDR      r4,[r7,#0x250]
        0x0000009e:    4643        CF      MOV      r3,r8
        0x000000a0:    4652        RF      MOV      r2,r10
        0x000000a2:    200d        .       MOVS     r0,#0xd
        0x000000a4:    47a0        .G      BLX      r4
        0x000000a6:    f8d74250    ..PB    LDR      r4,[r7,#0x250]
        0x000000aa:    4643        CF      MOV      r3,r8
        0x000000ac:    465a        ZF      MOV      r2,r11
        0x000000ae:    46a4        .F      MOV      r12,r4
        0x000000b0:    e8bd5ff0    ..._    POP      {r4-r12,lr}
        0x000000b4:    2104        .!      MOVS     r1,#4
        0x000000b6:    2018        .       MOVS     r0,#0x18
        0x000000b8:    4760        `G      BX       r12

This is basically 2 calls to the same function with different arguments
The second call is done using BX r12, but see that before that the contents of r12 are corrupted using the POP {r4-r12,lr} instruction.

Does anyone has any clue why does this happen. Or is this a known bug?
I have also attached the C code for someone to test.