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Update mov_FAC1_FAC2 to match the original implementation

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Rikard Nordgren authored and FeralChild64 committed 2026-01-25 19:22:33 +01:00
1 parent 0e6e0a5fc4
commit ee3c8cb11d
11 files changed
+110 -71
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LICENSE
+23
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@@ -19,3 +19,26 @@ including each source file, unless otherwise noted in each file or directory.
along with this program. If not, see <https://www.gnu.org/licenses/>.
Some BASIC files (noted in the specific files) are subject to this license and copyright:
MIT License
Copyright (c) Microsoft Corporation.
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE
Makefile
+1 -1
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@@ -931,7 +931,7 @@ testremote: build/kernal_custom.rom build/basic_custom.rom $(TARGET_CHR_PXL) bui
testsimilarity: $(TOOL_SIMILARITY) $(DIR_GEN)/OUTx_x.BIN $(ROM_CBM_KERNAL) $(ROM_CBM_BASIC)
$(TOOL_SIMILARITY) $(ROM_CBM_KERNAL) $(DIR_GEN)/OUTx_x.BIN
$(TOOL_SIMILARITY) $(ROM_CBM_BASIC) $(DIR_GEN)/OUTx_x.BIN
$(TOOL_SIMILARITY) $(ROM_CBM_BASIC) $(DIR_GEN)/OUTx_x.BIN --basic
build/testresults: testsuite/unit/testresults.cc
$(CXX) -std=c++20 -O2 -Wall -o $@ $<
STATUS.md
+2 -2
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@@ -228,8 +228,8 @@ Floating point mathematical routines - not official, but well known and broadly
| `$BBD0` | `mov_r_FAC1_VAR` | PARTIAL | not fully tested yet |
| `$BBD4` | `mov_r_FAC1_MEM` | PARTIAL | not fully tested yet |
| `$BBFC` | `mov_FAC2_FAC1` | DONE | |
| `$BC0C` | `mov_r_FAC1_FAC2` | PARTIAL | not fully tested yet |
| `$BC0F` | `mov_FAC1_FAC2` | DONE | |
| `$BC0C` | `mov_r_FAC1_FAC2` | DONE | From the Microsoft BASIC, original name: MOVAF |
| `$BC0F` | `mov_FAC1_FAC2` | DONE | From the Microsoft BASIC, original name: MOVEF |
| `$BC1B` | `round_FAC1` | PARTIAL | not fully tested yet |
| `$BC2B` | `sgn_FAC1_A` | DONE | |
| `$BC39` | `sgn_FAC1` | DONE | |
src/basic/math_mov/bc0c.mov_r_FAC1_FAC2.s
+6
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@@ -3,13 +3,19 @@
;; #LAYOUT# * BASIC_0 #TAKE
;; #LAYOUT# * * #IGNORE
; This file is under the MIT license, it contains code released by Microsoft Corporation.
; See LICENSE for more information.
;
; Math package - round and move FAC1 to FAC2
;
; This is identical to the original Microsoft implementation where it was named MOVAF.
;
; Output:
; - .A - FAC1 exponent
;
; See also:
; - https://github.com/microsoft/BASIC-M6502/blob/7460af2c03ae19c0e60ff327489229d2005b9357/m6502.asm#L5540C1-L5548C12
; - [CM64] Computes Mapping the Commodore 64 - page 115
; - https://www.c64-wiki.com/wiki/BASIC-ROM
; - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
src/basic/math_mov/bc0f.mov_FAC1_FAC2.jmp.s
-8
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@@ -1,8 +0,0 @@
;; #LAYOUT# STD * #TAKE
;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
;; #LAYOUT# * BASIC_0 #TAKE
;; #LAYOUT# * * #IGNORE
; Just a compatibility jump - our routine is longer than original one
jmp mov_FAC1_FAC2
src/basic/math_mov/bc0f.mov_FAC1_FAC2.s
+41
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@@ -0,0 +1,41 @@
;; #LAYOUT# STD * #TAKE
;; #LAYOUT# X16 BASIC_0 #TAKE-OFFSET 2000
;; #LAYOUT# * BASIC_0 #TAKE
;; #LAYOUT# * * #IGNORE
; This file is under the MIT license, it contains code released by Microsoft Corporation.
; See LICENSE for more information.
;
; Math package - move FAC1 to FAC2
;
; This is verified to be identical to the original Microsoft implementation where it was named MOVEF.
;
; Output:
; - .A - FAC1 exponent
; - .X - always 0
; Preserves:
; - .Y
;
; Note:
; - Always clears FACOV, not sure why
;
; See also:
; - https://github.com/microsoft/BASIC-M6502/blob/7460af2c03ae19c0e60ff327489229d2005b9357/m6502.asm#L5540C1-L5548C12
; - [CM64] Computes Mapping the Commodore 64 - page 115
; - https://www.c64-wiki.com/wiki/BASIC-ROM
; - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
;
mov_FAC1_FAC2:
ldx #6
@1
lda FAC1_exponent - 1,X
sta FAC2_exponent - 1,X
dex
bne @1
stx FACOV ; Always zero
rts
src/basic/math_mov/mov_FAC1_FAC2.s
-51
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@@ -1,51 +0,0 @@
;; #LAYOUT# STD * #TAKE
;; #LAYOUT# * BASIC_0 #TAKE
;; #LAYOUT# * * #IGNORE
;
; Math package - move FAC1 to FAC2
;
; Output (all found by experimentation):
; - .A - FAC1 exponent
; - .X - always 0
;
; Preserves (found by experimentation):
; - .Y
;
; Note:
; - observed that original ROM always clears FACOV, not sure why
;
; See also:
; - [CM64] Computes Mapping the Commodore 64 - page 115
; - https://www.c64-wiki.com/wiki/BASIC-ROM
; - https://www.c64-wiki.com/wiki/Floating_point_arithmetic
;
mov_FAC1_FAC2:
; Copy the exponent
lda FAC1_exponent
sta FAC2_exponent
beq @1 ; for 0 no need to copy mantissa and sign
; Copy the mantissa
lda FAC1_mantissa+0
sta FAC2_mantissa+0
lda FAC1_mantissa+1
sta FAC2_mantissa+1
lda FAC1_mantissa+2
sta FAC2_mantissa+2
lda FAC1_mantissa+3
sta FAC2_mantissa+3
; Copy the sign
lda FAC1_sign
sta FAC2_sign
lda FAC1_exponent
@1:
; Duplicate the original ROM behaviour
ldx #$00
stx FACOV
rts
strings/0000000003
+3
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@@ -0,0 +1,3 @@
00 00 00 00 03
Mostly NULL
strings/BC68203CBC
+3
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@@ -0,0 +1,3 @@
$BD + PLA + JSR $BC3C
Fragment + jump to well known floating point subroutine
strings/CAD0F9867060
+3
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@@ -0,0 +1,3 @@
DEX + BNE $F9 + STX $70 + RTS
Loop fragment + store to well known zero page location
tools/similarity.c
+28 -9
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@@ -20,20 +20,31 @@ int matches[MAX_SIZE];
int phase_mask[MAX_SIZE+MAX_SIZE];
#define NUM_CHUNKS 1
// Pairs of start, end memory addresses of known exact similarity with the open source Microsoft BASIC
unsigned short microsoft_basic_chunks[NUM_CHUNKS * 2] = {0xBC0C, 0xBC1A};
int main(int argc,char **argv)
{
int verbose=0;
int basic = 0;
if (argc<3) {
fprintf(stderr,"usage: similarity <file1> <file2> [verbose]\n");
fprintf(stderr,"usage: similarity <file1> <file2> [--verbose] [--basic]\n");
exit(-1);
}
if (argc==4) {
if (!strcmp(argv[3],"verbose")) verbose=1;
else {
fprintf(stderr,"Unrecognised directive.\n");
exit(-1);
}
if (argc >= 4) {
for (int i = 3; i < argc; i++) {
if (!strcmp(argv[i], "--verbose")) {
verbose = 1;
} else if (!strcmp(argv[i], "--basic")) {
basic = 1;
} else {
fprintf(stderr, "Unrecognised directive.\n");
exit(-1);
}
}
}
for(int i=0;i<MAX_SIZE;i++) matches[i]=0;
@@ -51,7 +62,7 @@ int main(int argc,char **argv)
}
stat(argv[1], &st);
s1=st.st_size;
f1 = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE | MAP_POPULATE, fd, 0);
f1 = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_POPULATE, fd, 0);
if (f1== MAP_FAILED) {
fprintf(stderr,"Could not mmap '%s'\n",argv[1]);
exit(-1);
@@ -69,6 +80,14 @@ int main(int argc,char **argv)
exit(-1);
}
if (basic) {
for (int i = 0; i < NUM_CHUNKS; i++) {
for (int addr = microsoft_basic_chunks[i * 2]; addr <= microsoft_basic_chunks[i * 2 + 1]; addr++) {
f1[addr - 0xA000] = 0;
}
}
}
fprintf(stderr,"Searching files for similarities...\n");
for(int i=0;i<s1;i++) {