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Diffstat (limited to 'runtime/powerpc/i64_scmp.s')
| -rw-r--r-- | runtime/powerpc/i64_scmp.s | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/runtime/powerpc/i64_scmp.s b/runtime/powerpc/i64_scmp.s new file mode 100644 index 0000000..8963006 --- /dev/null +++ b/runtime/powerpc/i64_scmp.s @@ -0,0 +1,72 @@ +# ***************************************************************** +# +# The Compcert verified compiler +# +# Xavier Leroy, INRIA Paris-Rocquencourt +# +# Copyright (c) 2013 Institut National de Recherche en Informatique et +# en Automatique. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are met: +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# * Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# * Neither the name of the <organization> nor the +# names of its contributors may be used to endorse or promote products +# derived from this software without specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT +# HOLDER> BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, +# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +# +# ********************************************************************* + +# Helper functions for 64-bit integer arithmetic. PowerPC version. + + .text + +### Unsigned comparison + + .balign 16 + .globl __i64_ucmp +__i64_ucmp: + cmpw cr0, r3, r5 # compare high words (signed) + cmplw cr1, r4, r6 # compare low words (unsigned) + mfcr r0 +# At this point, the bits of r0 are as follow: +# bit 31: XH < YH +# bit 30: XH > YH +# bit 27: XL > YL +# bit 26: XL < YL + rlwinm r3, r0, 0, 0, 1 # r3 = r0 & 0xC000_0000 + srawi r3, r3, 24 # r4 = r4 >>s 28 +# r3 = -0x80 if XH < YH +# = 0x40 if XH > YH +# = 0 if XH = YH + rlwinm r4, r0, 4, 0, 1 # r4 = (r0 << 4) & 0xC000_0000 + srawi r4, r4, 28 # r4 = r4 >>s 28 +# r4 = -8 if XL < YL +# = 4 if XL > YL +# = 0 if XL = YL + add r3, r3, r4 +# r3 = -0x80 or -0x80 - 8 or -0x80 + 4 or -8 if X < Y +# (in all cases, r3 < 0 if X < Y) +# = 0x40 or 0x40 - 8 or 0x40 + 4 or 4 if X > Y +# (in all cases, r3 > 0 if X > Y) +# = 0 if X = Y + blr + .type __i64_scmp, @function + .size __i64_scmp, .-__i64_ucmp + +
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