user: 请从给定的汇编指令推导出C源代码:

```asm
<softfloat_shiftRightJam256M>:
  endbr64
  push   %r14
  mov    %rdi,%r8
  push   %r13
  mov    %esi,%r13d
  sar    $0x6,%esi
  push   %r12
  mov    %rdx,%r12
  push   %rbp
  push   %rbx
  je     L9
  mov    $0x4,%eax
  cmp    %eax,%esi
  cmovle %esi,%eax
  mov    %eax,%ecx
  lea    -0x1(%rax),%eax
  mov    %rax,%r14
  lea    0x4(%rdi,%rax,4),%rdx
  mov    %rdi,%rax
  jmp    L81
  cs nopw 0x0(%rax,%rax,1)
L55:
  cmp    %rdx,%rax
  je     L47
L81:
  mov    (%rax),%ebx
  add    $0x4,%rax
  test   %ebx,%ebx
  je     L55
  cmp    $0x3,%esi
  jle    L79
  pxor   %xmm0,%xmm0
  movups %xmm0,(%r12)
  jmp    L105
  nopw   0x0(%rax,%rax,1)
L9:
  test   %r13d,%r13d
  jne    L71
  mov    $0x10,%edi
  mov    $0x4,%ebp
  mov    $0xffffffff,%r14d
L198:
  lea    0x4(%r8),%rdx
  mov    %r12,%rax
  sub    %rdx,%rax
  cmp    $0x8,%rax
  jbe    L132
  lea    -0x1(%rbp),%eax
  cmp    $0x2,%eax
  jbe    L132
  mov    %ebp,%edx
  xor    %eax,%eax
  shr    $0x2,%edx
  shl    $0x4,%rdx
  nopl   0x0(%rax)
L33:
  movdqu (%r8,%rax,1),%xmm1
  movups %xmm1,(%r12,%rax,1)
  add    $0x10,%rax
  cmp    %rdx,%rax
  jne    L33
  mov    %ebp,%edx
  mov    %ebp,%ecx
  and    $0xfffffffc,%edx
  mov    %edx,%eax
  sub    %edx,%ecx
  shl    $0x2,%rax
  add    %rax,%r8
  add    %r12,%rax
  cmp    %edx,%ebp
  je     L126
  mov    (%r8),%edx
  mov    %edx,(%rax)
  cmp    $0x1,%ecx
  je     L126
  mov    0x4(%r8),%edx
  mov    %edx,0x4(%rax)
  cmp    $0x2,%ecx
  je     L126
  mov    0x8(%r8),%edx
  mov    %edx,0x8(%rax)
L126:
  mov    %r14d,%r14d
  add    %r12,%rdi
  xor    %esi,%esi
  lea    0x4(,%r14,4),%rdx
  call   <memset@plt>
  test   %r13d,%r13d
  je     L133
L105:
  orl    $0x1,(%r12)
L133:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
  nopw   0x0(%rax,%rax,1)
L47:
  cmp    $0x3,%esi
  jle    L79
  pxor   %xmm0,%xmm0
  pop    %rbx
  pop    %rbp
  movups %xmm0,(%r12)
  pop    %r12
  pop    %r13
  pop    %r14
  ret
  nopw   0x0(%rax,%rax,1)
L79:
  movslq %ecx,%rax
  mov    $0x4,%ebp
  mov    %r13d,%edx
  lea    (%r8,%rax,4),%r8
  sub    %ecx,%ebp
  and    $0x3f,%edx
  je     L19
  mov    %ebp,%edi
  mov    %r12,%rcx
  mov    %r8,%rsi
  mov    %ebx,%r13d
  call   <softfloat_shortShiftRightJamM@plt>
  movslq %ebp,%rdi
  shl    $0x2,%rdi
  jmp    L126
L71:
  pop    %rbx
  mov    %rdx,%rcx
  pop    %rbp
  mov    %r13d,%edx
  pop    %r12
  mov    %rdi,%rsi
  pop    %r13
  mov    $0x4,%edi
  pop    %r14
  jmp    1070 <softfloat_shortShiftRightJamM@plt>
  nopw   0x0(%rax,%rax,1)
L132:
  movslq %ebp,%rbp
  xor    %eax,%eax
  nopl   (%rax)
L146:
  mov    (%r8,%rax,4),%edx
  mov    %edx,(%r12,%rax,4)
  add    $0x1,%rax
  cmp    %rax,%rbp
  jne    L146
  jmp    L126
L19:
  movslq %ebp,%rdi
  mov    %ebx,%r13d
  shl    $0x2,%rdi
  jmp    L198
```

assistant: ```c
void softfloat_shiftRightJam256M(const uint64_t *aPtr, uint_fast32_t count, uint64_t *zPtr) {
  uint64_t wordJam;
  uint_fast32_t wordCount;
  uint64_t *ptr;
  uint_fast8_t i, innerCount;
  wordJam = 0;
  wordCount = count >> 6;
  if (wordCount) {
    if (4 < wordCount)
      wordCount = 4;
    ptr = (uint64_t *)(aPtr + 0);
    i = wordCount;
    do {
      wordJam = *ptr++;
      if (wordJam)
        break;
      --i;
    } while (i);
    ptr = zPtr;
  }
  if (wordCount < 4) {
    aPtr += (wordCount);
    innerCount = count & 63;
    if (innerCount) {
      softfloat_shortShiftRightJamM(4 - wordCount, aPtr, innerCount, zPtr + 0);
      if (!wordCount)
        goto wordJam;
    } else {
      aPtr += 0;
      ptr = zPtr + 0;
      for (i = 4 - wordCount; i; --i) {
        *ptr = *aPtr;
        aPtr += 1;
        ptr += 1;
      }
    }
    ptr = zPtr + ((4) - (wordCount));
  }
  do {
    *ptr++ = 0;
    --wordCount;
  } while (wordCount);
wordJam:
  if (wordJam)
    zPtr[0] |= 1;
}
```