ref: 4b33eb05dc283b41b0c638ffd0b2ceb619f0f1dd
dir: /build/make/ads2gas.pl/
#!/usr/bin/perl
##
## Copyright (c) 2010 The WebM project authors. All Rights Reserved.
##
## Use of this source code is governed by a BSD-style license
## that can be found in the LICENSE file in the root of the source
## tree. An additional intellectual property rights grant can be found
## in the file PATENTS. All contributing project authors may
## be found in the AUTHORS file in the root of the source tree.
##
# ads2gas.pl
# Author: Eric Fung (efung (at) acm.org)
#
# Convert ARM Developer Suite 1.0.1 syntax assembly source to GNU as format
#
# Usage: cat inputfile | perl ads2gas.pl > outputfile
#
my $thumb = 0;
foreach my $arg (@ARGV) {
$thumb = 1 if ($arg eq "-thumb");
}
print "@ This file was created from a .asm file\n";
print "@ using the ads2gas.pl script.\n";
print "\t.equ DO1STROUNDING, 0\n";
if ($thumb) {
print "\t.syntax unified\n";
print "\t.thumb\n";
}
# Stack of procedure names.
@proc_stack = ();
while (<STDIN>)
{
undef $comment;
undef $line;
$comment_char = ";";
$comment_sub = "@";
# Handle comments.
if (/$comment_char/)
{
$comment = "";
($line, $comment) = /(.*?)$comment_char(.*)/;
$_ = $line;
}
# Load and store alignment
s/@/,:/g;
# Hexadecimal constants prefaced by 0x
s/#&/#0x/g;
# Convert :OR: to |
s/:OR:/ | /g;
# Convert :AND: to &
s/:AND:/ & /g;
# Convert :NOT: to ~
s/:NOT:/ ~ /g;
# Convert :SHL: to <<
s/:SHL:/ << /g;
# Convert :SHR: to >>
s/:SHR:/ >> /g;
# Convert ELSE to .else
s/\bELSE\b/.else/g;
# Convert ENDIF to .endif
s/\bENDIF\b/.endif/g;
# Convert ELSEIF to .elseif
s/\bELSEIF\b/.elseif/g;
# Convert LTORG to .ltorg
s/\bLTORG\b/.ltorg/g;
# Convert endfunc to nothing.
s/\bendfunc\b//ig;
# Convert FUNCTION to nothing.
s/\bFUNCTION\b//g;
s/\bfunction\b//g;
s/\bENTRY\b//g;
s/\bMSARMASM\b/0/g;
s/^\s+end\s+$//g;
# Convert IF :DEF:to .if
# gcc doesn't have the ability to do a conditional
# if defined variable that is set by IF :DEF: on
# armasm, so convert it to a normal .if and then
# make sure to define a value elesewhere
if (s/\bIF :DEF:\b/.if /g)
{
s/=/==/g;
}
# Convert IF to .if
if (s/\bIF\b/.if/g)
{
s/=+/==/g;
}
# Convert INCLUDE to .INCLUDE "file"
s/INCLUDE(\s*)(.*)$/.include $1\"$2\"/;
# Code directive (ARM vs Thumb)
s/CODE([0-9][0-9])/.code $1/;
# No AREA required
# But ALIGNs in AREA must be obeyed
s/^\s*AREA.*ALIGN=([0-9])$/.text\n.p2align $1/;
# If no ALIGN, strip the AREA and align to 4 bytes
s/^\s*AREA.*$/.text\n.p2align 2/;
# DCD to .word
# This one is for incoming symbols
s/DCD\s+\|(\w*)\|/.long $1/;
# DCW to .short
s/DCW\s+\|(\w*)\|/.short $1/;
s/DCW(.*)/.short $1/;
# Constants defined in scope
s/DCD(.*)/.long $1/;
s/DCB(.*)/.byte $1/;
# RN to .req
if (s/RN\s+([Rr]\d+|lr)/.req $1/)
{
print;
print "$comment_sub$comment\n" if defined $comment;
next;
}
# Make function visible to linker, and make additional symbol with
# prepended underscore
s/EXPORT\s+\|([\$\w]*)\|/.global $1 \n\t.type $1, function/;
s/IMPORT\s+\|([\$\w]*)\|/.global $1/;
s/EXPORT\s+([\$\w]*)/.global $1/;
s/export\s+([\$\w]*)/.global $1/;
# No vertical bars required; make additional symbol with prepended
# underscore
s/^\|(\$?\w+)\|/_$1\n\t$1:/g;
# Labels need trailing colon
# s/^(\w+)/$1:/ if !/EQU/;
# put the colon at the end of the line in the macro
s/^([a-zA-Z_0-9\$]+)/$1:/ if !/EQU/;
# ALIGN directive
s/\bALIGN\b/.balign/g;
if ($thumb) {
# ARM code - we force everything to thumb with the declaration in the header
s/\sARM//g;
} else {
# ARM code
s/\sARM/.arm/g;
}
# push/pop
s/(push\s+)(r\d+)/stmdb sp\!, \{$2\}/g;
s/(pop\s+)(r\d+)/ldmia sp\!, \{$2\}/g;
# NEON code
s/(vld1.\d+\s+)(q\d+)/$1\{$2\}/g;
s/(vtbl.\d+\s+[^,]+),([^,]+)/$1,\{$2\}/g;
if ($thumb) {
# Write additions with shifts, such as "add r10, r11, lsl #8",
# in three operand form, "add r10, r10, r11, lsl #8".
s/(add\s+)(r\d+),\s*(r\d+),\s*(lsl #\d+)/$1$2, $2, $3, $4/g;
# Convert additions with a non-constant shift into a sequence
# with left shift, addition and a right shift (to restore the
# register to the original value). Currently the right shift
# isn't necessary in the code base since the values in these
# registers aren't used, but doing the shift for consitency.
# This converts instructions such as "add r12, r12, r5, lsl r4"
# into the sequence "lsl r5, r4", "add r12, r12, r5", "lsr r5, r4".
s/^(\s*)(add)(\s+)(r\d+),\s*(r\d+),\s*(r\d+),\s*lsl (r\d+)/$1lsl$3$6, $7\n$1$2$3$4, $5, $6\n$1lsr$3$6, $7/g;
# Convert loads with right shifts in the indexing into a
# sequence of an add, load and sub. This converts
# "ldrb r4, [r9, lr, asr #1]" into "add r9, r9, lr, asr #1",
# "ldrb r9, [r9]", "sub r9, r9, lr, asr #1".
s/^(\s*)(ldrb)(\s+)(r\d+),\s*\[(\w+),\s*(\w+),\s*(asr #\d+)\]/$1add $3$5, $5, $6, $7\n$1$2$3$4, [$5]\n$1sub $3$5, $5, $6, $7/g;
# Convert register indexing with writeback into a separate add
# instruction. This converts "ldrb r12, [r1, r2]!" into
# "ldrb r12, [r1, r2]", "add r1, r1, r2".
s/^(\s*)(ldrb)(\s+)(r\d+),\s*\[(\w+),\s*(\w+)\]!/$1$2$3$4, [$5, $6]\n$1add $3$5, $6/g;
# Convert negative register indexing into separate sub/add instructions.
# This converts "ldrne r4, [src, -pstep, lsl #1]" into
# "subne src, src, pstep, lsl #1", "ldrne r4, [src]",
# "addne src, src, pstep, lsl #1". In a couple of cases where
# this is used, it's used for two subsequent load instructions,
# where a hand-written version of it could merge two subsequent
# add and sub instructions.
s/^(\s*)((ldr|str)(ne)?)(\s+)(r\d+),\s*\[(\w+), -([^\]]+)\]/$1sub$4$5$7, $7, $8\n$1$2$5$6, [$7]\n$1add$4$5$7, $7, $8/g;
# Convert register post indexing to a separate add instruction.
# This converts "ldrneb r9, [r0], r2" into "ldrneb r9, [r0]",
# "add r0, r2".
s/^(\s*)((ldr|str)(ne)?[bhd]?)(\s+)(\w+),(\s*\w+,)?\s*\[(\w+)\],\s*(\w+)/$1$2$5$6,$7 [$8]\n$1add$4$5$8, $8, $9/g;
# Convert a conditional addition to the pc register into a series of
# instructions. This converts "addlt pc, pc, r3, lsl #2" into
# "ittt lt", "addlt.w r12, pc, #10", "addlt.w r12, r12, r3, lsl #2",
# "movlt.n pc, r12". This assumes that r12 is free at this point.
s/^(\s*)addlt(\s+)pc,\s*pc,\s*(\w+),\s*lsl\s*#(\d+)/$1ittt$2lt\n$1addlt.w$2r12, pc, #10\n$1addlt.w$2r12, r12, $3, lsl #$4\n$1movlt.n$2pc, r12/g;
# Convert "mov pc, lr" into "bx lr", since the former only works
# for switching from arm to thumb (and only in armv7), but not
# from thumb to arm.
s/mov(\s*)pc\s*,\s*lr/bx$1lr/g;
}
# eabi_attributes numerical equivalents can be found in the
# "ARM IHI 0045C" document.
# REQUIRE8 Stack is required to be 8-byte aligned
s/\sREQUIRE8/.eabi_attribute 24, 1 \@Tag_ABI_align_needed/g;
# PRESERVE8 Stack 8-byte align is preserved
s/\sPRESERVE8/.eabi_attribute 25, 1 \@Tag_ABI_align_preserved/g;
# Use PROC and ENDP to give the symbols a .size directive.
# This makes them show up properly in debugging tools like gdb and valgrind.
if (/\bPROC\b/)
{
my $proc;
/^_([\.0-9A-Z_a-z]\w+)\b/;
$proc = $1;
push(@proc_stack, $proc) if ($proc);
s/\bPROC\b/@ $&/;
}
if (/\bENDP\b/)
{
my $proc;
s/\bENDP\b/@ $&/;
$proc = pop(@proc_stack);
$_ = "\t.size $proc, .-$proc".$_ if ($proc);
}
# EQU directive
s/(\S+\s+)EQU(\s+\S+)/.equ $1, $2/;
# Begin macro definition
if (/\bMACRO\b/) {
$_ = <STDIN>;
s/^/.macro/;
s/\$//g; # remove formal param reference
s/;/@/g; # change comment characters
}
# For macros, use \ to reference formal params
s/\$/\\/g; # End macro definition
s/\bMEND\b/.endm/; # No need to tell it where to stop assembling
next if /^\s*END\s*$/;
print;
print "$comment_sub$comment\n" if defined $comment;
}
# Mark that this object doesn't need an executable stack.
printf ("\t.section\t.note.GNU-stack,\"\",\%\%progbits\n");