diff options
Diffstat (limited to 'runtime/powerpc/i64_udivmod.s')
| -rw-r--r-- | runtime/powerpc/i64_udivmod.s | 234 |
1 files changed, 0 insertions, 234 deletions
diff --git a/runtime/powerpc/i64_udivmod.s b/runtime/powerpc/i64_udivmod.s deleted file mode 100644 index e81c6cef..00000000 --- a/runtime/powerpc/i64_udivmod.s +++ /dev/null @@ -1,234 +0,0 @@ -# ***************************************************************** -# -# 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 division and modulus - -# This function computes both the quotient and the remainder of two -# unsigned 64-bit integers. - -# Input: numerator N in (r3,r4), divisor D in (r5,r6) -# Output: quotient Q in (r5,r6), remainder R in (r3,r4) -# Destroys: all integer caller-save registers - - .globl __compcert_i64_udivmod - .balign 16 -__compcert_i64_udivmod: - cmplwi r5, 0 # DH == 0 ? - stwu r1, -32(r1) - mflr r0 - stw r0, 8(r1) - stw r31, 12(r1) - beq 1f -# The general case - stw r30, 16(r1) - stw r29, 20(r1) - stw r28, 24(r1) - mr r28, r3 # Save N in (r28, r29) - mr r29, r4 - mr r30, r5 # Save D in (r30, r31) - mr r31, r6 - # Scale N and D down, giving N' and D', such that 2^31 <= D' < 2^32 - cntlzw r7, r5 # r7 = leading zeros in DH = 32 - shift amount - subfic r8, r7, 32 # r8 = shift amount - slw r0, r3, r7 # N' = N >> shift amount - srw r3, r3, r8 - srw r4, r4, r8 - or r4, r4, r0 - slw r0, r5, r7 # D' = D >> shift amount - srw r6, r6, r8 - or r5, r6, r0 - # Divide N' by D' to get an approximate quotient Q - bl __compcert_i64_udiv6432 # r3 = quotient, r4 = remainder - mr r6, r3 # low half of quotient Q - li r5, 0 # high half of quotient is 0 - # Tentative quotient is either correct or one too high - # Compute Q * D in (r7, r8) -4: mullw r7, r6, r30 # r7 = Q * DH - mullw r8, r6, r31 # r8 = low 32 bits of Q * DL - mulhwu r0, r6, r31 # r0 = high 32 bits of Q * DL - addc r7, r7, r0 - subfe. r0, r0, r0 # test carry: EQ iff carry - beq 2f # handle overflow case - # Compute R = N - Q * D, with borrow - subfc r4, r8, r29 - subfe r3, r7, r28 - subfe. r0, r0, r0 # test borrow: EQ iff no borrow - beq 3f # no borrow: N >= Q * D, we are good - addi r6, r6, -1 # borrow: adjust Q down by 1 - addc r4, r4, r31 # and R up by D - adde r3, r3, r30 - # Finished -3: lwz r0, 8(r1) - mtlr r0 - lwz r31, 12(r1) - lwz r30, 16(r1) - lwz r29, 20(r1) - lwz r28, 24(r1) - addi r1, r1, 32 - blr - # Special case when Q * D overflows -2: addi r6, r6, -1 # adjust Q down by 1 - b 4b # and redo computation and check of remainder - .balign 16 -# Special case 64 bits divided by 32 bits -1: cmplwi r3, 0 # NH == 0? - beq 4f - divwu r31, r3, r6 # Divide NH by DL, quotient QH in r31 - mullw r0, r31, r6 - subf r3, r0, r3 # NH is remainder of this division - mr r5, r6 - bl __compcert_i64_udiv6432 # divide NH : NL by DL - mr r5, r31 # high word of quotient - mr r6, r3 # low word of quotient - # r4 contains low word of remainder - li r3, 0 # high word of remainder = 0 - lwz r0, 8(r1) - mtlr r0 - lwz r31, 12(r1) - addi r1, r1, 32 - blr - .balign 16 -# Special case 32 bits divided by 32 bits -4: mr r0, r6 - divwu r6, r4, r6 # low word of quotient - li r5, 0 # high word of quotient is 0 - mullw r0, r6, r0 - subf r4, r0, r4 # low word of remainder - li r3, 0 # high word of remainder is 0 - addi r1, r1, 32 - blr - - .type __compcert_i64_udivmod, @function - .size __compcert_i64_udivmod, .-__compcert_i64_udivmod - -# Auxiliary division function: 64 bit integer divided by 32 bit integer -# Not exported -# Input: numerator N in (r3,r4), divisor D in r5 -# Output: quotient Q in r3, remainder R in r4 -# Destroys: all integer caller-save registers -# Assumes: high word of N is less than D - - .balign 16 -__compcert_i64_udiv6432: -# Algorithm 9.3 from Hacker's Delight, section 9.4 -# Initially: u1 in r3, u0 in r4, v in r5 -# s = __builtin_clz(v); - cntlzw r6, r5 # s in r6 -# v = v << s; - slw r5, r5, r6 -# vn1 = v >> 16; # vn1 in r7 - srwi r7, r5, 16 -# vn0 = v & 0xFFFF; # vn0 in r8 - rlwinm r8, r5, 0, 16, 31 -# un32 = (u1 << s) | (u0 >> 32 - s); - subfic r0, r6, 32 - srw r0, r4, r0 - slw r3, r3, r6 # u1 dies, un32 in r3 - or r3, r3, r0 -# un10 = u0 << s; - slw r4, r4, r6 # u0 dies, un10 in r4 -# un1 = un10 >> 16; - srwi r9, r4, 16 # un1 in r9 -# un0 = un10 & 0xFFFF; - rlwinm r4, r4, 0, 16, 31 # un10 dies, un0 in r4 -# q1 = un32/vn1; - divwu r10, r3, r7 # q in r10 -# rhat = un32 - q1*vn1; - mullw r0, r10, r7 - subf r11, r0, r3 # rhat in r11 -# again1: -1: -# if (q1 >= b || q1*vn0 > b*rhat + un1) { - cmplwi r10, 0xFFFF - bgt 2f - mullw r0, r10, r8 - slwi r12, r11, 16 - add r12, r12, r9 - cmplw r0, r12 - ble 3f -2: -# q1 = q1 - 1; - addi r10, r10, -1 -# rhat = rhat + vn1; - add r11, r11, r7 -# if (rhat < b) goto again1;} - cmplwi r11, 0xFFFF - ble 1b -3: -# un21 = un32*b + un1 - q1*v; - slwi r0, r3, 16 # un32 dies - add r9, r0, r9 # un1 dies - mullw r0, r10, r5 - subf r9, r0, r9 # un21 in r9 -# q0 = un21/vn1; - divwu r3, r9, r7 # q0 in r3 -# rhat = un21 - q0*vn1; - mullw r0, r3, r7 - subf r11, r0, r9 # rhat in r11 -# again2: -4: -# if (q0 >= b || q0*vn0 > b*rhat + un0) { - cmplwi r3, 0xFFFF - bgt 5f - mullw r0, r3, r8 - slwi r12, r11, 16 - add r12, r12, r4 - cmplw r0, r12 - ble 6f -5: -# q0 = q0 - 1; - addi r3, r3, -1 -# rhat = rhat + vn1; - add r11, r11, r7 -# if (rhat < b) goto again2;} - cmplwi r11, 0xFFFF - ble 4b -6: -# remainder = (un21*b + un0 - q0*v) >> s; - slwi r0, r9, 16 - add r4, r0, r4 # un0 dies, remainder in r4 - mullw r0, r3, r5 - subf r4, r0, r4 - srw r4, r4, r6 -# quotient = q1*b + q0; - slwi r0, r10, 16 - add r3, r0, r3 - blr - - .type __compcert_i64_udiv6432, @function - .size __compcert_i64_udiv6432,.-__compcert_i64_udiv6432 |