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# Copyright (C) 2003 MySQL AB
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation; version 2 of the License.
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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# Implemention of my_strtoll(): Converting a string to a 64 bit integer.
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# For documentation, check my_strtoll.c
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.file "my_strtoll10-x86.s"
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.type my_strtoll10,@function
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# Used stack variables
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# ebp-4 dummy for storing endptr if endptr = 0
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# ebp-8 First 9 digits of return values
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# ebp-12 Pointer to first digit of second part
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# ebp-16 Store lowest 2 digits
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# ebp-20 != 0 if value was negative
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# ebp-24 High max value
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# ebp-28 Middle max value
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# ebp-32 Low max value
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# esi Pointer to input string
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movl 8(%ebp),%esi # esi= nptr
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movl 16(%ebp),%ecx # ecx= error (Will be overwritten later)
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movl 12(%ebp),%eax # eax= endptr
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cmpl $0,%eax # if (endptr)
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movl (%eax),%ebx # bx= end-of-string
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movb (%esi), %al # al= next byte
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cmpb $32,%al # Skip space
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cmpb $9,%al # Skip tab
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# String that ends with \0
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movl %edi,12(%ebp) # endptr= &dummy, for easier end check
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movb (%esi), %al # al= next byte
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testb %al,%al # Test if we found end \0
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leal 65535(%esi),%ebx # ebx = end-of-string
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cmpb $45,%al # Test if '-'
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movl $-1,(%ecx) # error = -1 (mark that number is negative)
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movl $1,-20(%ebp) # negative= 1
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movl $92233720,-24(%ebp)
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movl $368547758,-28(%ebp)
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movl $0,(%ecx) # error=0
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movl $0,-20(%ebp) # negative= 0
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movl $184467440,-24(%ebp)
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movl $737095516,-28(%ebp)
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cmpb $43,%al # Check if '+'
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cmpl %ebx,%esi # Check if overflow
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movb (%esi), %al # al= next byte after sign
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# Remove pre zero to be able to handle a lot of pre-zero
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jne .L475 # Number doesn't start with 0
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incl %esi # Skip processed byte
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cmpb (%esi),%al # Test if next byte is also zero
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leal 9(%esi),%ecx # ecx = end-of-current-part
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xorl %edi,%edi # Store first 9 digits in edi
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# Check if first char is a valid number
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movzbl %al,%edi # edi = first digit
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leal 8(%esi),%ecx # ecx = end-of-current-part
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# Handle first 8/9 digits and store them in edi
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movl %ebx,%ecx # ecx = min(end-of-current-part, end-of-string)
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movb (%esi), %al # al= next byte
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# Calculate edi= edi*10 + al
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leal (%edi,%edi,4),%edx
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leal (%eax,%edx,2),%edi
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cmpl %ecx,%esi # If more digits at this level
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cmpl %ebx,%esi # If end of string
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movl %edi,-8(%ebp) # Store first 9 digits
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movl %esi,-12(%ebp) # store pos to first digit of second part
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# Calculate next 9 digits and store them in edi
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leal 9(%esi),%ecx # ecx= end-of-current-part
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movl %ecx,-36(%ebp) # Store max length
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movl %ebx,%ecx # ecx = min(end-of-current-part, end-of-string)
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movb (%esi), %al # al= next byte
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ja .Lend_i_and_j_decl_esi
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# Calculate edi= edi*10 + al
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leal (%edi,%edi,4),%edx
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leal (%eax,%edx,2),%edi
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cmpl %ecx,%esi # If end of current part
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cmpl %ebx,%esi # If end of string
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cmpl -36(%ebp),%esi # Test if string is less than 18 digits
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movl $1000000000,%eax
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jmp .Lgot_factor # 18 digit string
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# Handle the possible next to last digit and store in ecx
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ja .L499 # 18 digit string
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cmpl %ebx,%esi # If end of string
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movb (%esi),%al # Read last digit
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leal (%ecx,%ecx,4),%edx
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leal (%eax,%edx,2),%ecx
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movl 12(%ebp),%eax # eax = endptr
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movl %esi,(%eax) # *endptr = end-of-string
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je .L505 # At end of string
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movb (%esi),%al # check if extra digits
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# At this point we have:
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# -8(%ebp) First 9 digits
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# *endpos end-of-string
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.L505: # Check that we are not going to get overflow for unsigned long long
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movl -8(%ebp),%eax # First 9 digits
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movl %edi,-4(%ebp) # Save middle bytes
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movl %ecx,%esi # esi = 2 last digits
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movl $1215752192,%ecx # %ecx= lower_32_bits(100000000000)
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imull $23,-8(%ebp),%ecx
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imull $1215752192,-36(%ebp),%eax
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addl %eax,%edi # Temp in edi:ebx
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movl $100,%eax # j= j*100
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addl %ebx,%eax # edx:eax+= edi:ebx
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# When we come here, *endptr is already updated
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movl 16(%ebp),%edx # edx= error
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movl $34,(%edx) # *error = 34
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cmpl $0,-20(%ebp) # If negative
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xor %eax,%eax # edx:eax = LONGLONG_LMIN
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movl $-2147483648,%edx
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# Return value that is in %edi as long long
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decl %esi # Fix so that it points at last digit
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je .Lreturn_save_endptr # Positive number
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cltd # Neg result in edx:eax
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jmp .Lreturn_save_endptr
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# Return value (%ebp-8) * lfactor[(uint) (edx-start)] + edi
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.Lend_i_and_j_decl_esi:
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decl %esi # Fix so that it points at last digit
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subl -12(%ebp),%ecx # ecx= number of digits in second part
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# Calculate %eax= 10 ** %cl, where %cl <= 8
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# With an array one could do this with:
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# movl 10_factor_table(,%ecx,4),%eax
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# We calculate the table here to avoid problems in
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# position independent code (gcc -pic)
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je .Lgot_factor # %cl=3, eax= 1000
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cmpb $1,%cl # %cl is here 0 - 2
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je .Lgot_factor # %cl=1, eax= 10
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ja .Lgot_factor # %cl=2, eax=100
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jmp .Lgot_factor # %cl=0, eax=1
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.L4_to_8: # %cl is here 4-8
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je .Lgot_factor # %cl=5, eax=100000
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jbe .Lgot_factor # %cl=4, eax=10000
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je .Lgot_factor # %cl=7, eax=10000000
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movl $100000000, %eax
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ja .Lgot_factor # %cl=8, eax=100000000
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movl $1000000, %eax # %cl=6, eax=1000000
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# Return -8(%ebp) * %eax + edi
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cmpl $0,-20(%ebp) # if negative
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je .Lreturn_save_endptr
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negl %eax # Neg edx:%eax
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jmp .Lreturn_save_endptr
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# Return -8(%ebp) * $10000000000 + edi*10 + ecx
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movl %ecx,-16(%ebp) # store lowest digits
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movl %esi,(%ebx) # *endpos = end-of-string
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movl -8(%ebp),%eax # First 9 digits
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movl $1410065408,%ecx # ecx= lower_32_bits(10000000000)
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movl %eax,%ebx # Store lowest 32 byte from multiplication
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imull $1410065408,-36(%ebp),%eax
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movl -8(%ebp),%ecx # First 9 digits
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addl %eax,%esi # %esi:%ebx now has -8(%ebp) * $10000000000
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movl $10,%eax # Calc edi*10
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addl %ebx,%eax # And add to result
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addl -16(%ebp),%eax # Add lowest digit
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cmpl $0,-20(%ebp) # if negative
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cmpl $-2147483648,%edx # Test if too big signed integer
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.Lno_conv: # Not a legal number
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movl $33,(%eax) # error= edom
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xorl %eax,%eax # Return zero
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.Lreturn_save_endptr:
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movl 12(%ebp),%ecx # endptr= end-of-string
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movl %esi,(%ecx) # *endptr= end-of-string
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.size my_strtoll10,.my_strtoll10_end-my_strtoll10
added
removed
strings/my_strtoll10-x86.s
