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authorPaul Selkirk <paul@psgd.org>2020-03-09 15:47:17 -0400
committerPaul Selkirk <paul@psgd.org>2020-03-09 15:50:12 -0400
commit38b388061364339c1259b56fe1d366de8b8630d3 (patch)
treee6243e7a5c8f8051d85510824dee551222015872 /libraries/libtfm
parent6b2513f1e0def3a134383aa635cb41feac37be31 (diff)
Replace the brutally inefficient fp_to_unsigned_bin with one based on
fp_read_unsigned_bin. I thought about patching it directly in sw/thirdparty/libtfm, but ultimately decided to keep that pristine (especially since we verify file checksums there).
Diffstat (limited to 'libraries/libtfm')
-rw-r--r--libraries/libtfm/Makefile7
-rw-r--r--libraries/libtfm/fp_to_unsigned_bin.c62
2 files changed, 67 insertions, 2 deletions
diff --git a/libraries/libtfm/Makefile b/libraries/libtfm/Makefile
index 34b9314..aa5031f 100644
--- a/libraries/libtfm/Makefile
+++ b/libraries/libtfm/Makefile
@@ -45,10 +45,12 @@ CFLAGS += -Wall -W -Wshadow -Wno-uninitialized
TARGETS := $(notdir ${HDR} ${LIB})
+REPLACE = fp_to_unsigned_bin.o
+
all: ${TARGETS}
clean:
- rm -rf ${TARGETS} $(notdir ${HDR}.tmp) ${LIB} tomsfastmath/src
+ rm -rf ${TARGETS} $(notdir ${HDR}.tmp) ${LIB} tomsfastmath/src ${REPLACE}
distclean: clean
rm -f TAGS
@@ -63,6 +65,7 @@ $(notdir ${HDR}): ${HDR}
$(notdir ${LIB}): ${LIB}
ln -f $^ $@
-${LIB}: ${HDR}
+${LIB}: ${HDR} ${REPLACE}
(cd ${LIBTFM_SRC} && find tomsfastmath/src -type d) | xargs mkdir -p
cd tomsfastmath; ${MAKE} CFLAGS='${CFLAGS}'
+ ar r ${LIB} ${REPLACE}
diff --git a/libraries/libtfm/fp_to_unsigned_bin.c b/libraries/libtfm/fp_to_unsigned_bin.c
new file mode 100644
index 0000000..618167d
--- /dev/null
+++ b/libraries/libtfm/fp_to_unsigned_bin.c
@@ -0,0 +1,62 @@
+/* TomsFastMath, a fast ISO C bignum library.
+ *
+ * This project is meant to fill in where LibTomMath
+ * falls short. That is speed ;-)
+ *
+ * This project is public domain and free for all purposes.
+ *
+ * Tom St Denis, tomstdenis@gmail.com
+ */
+#include <tfm_private.h>
+
+void fp_to_unsigned_bin(fp_int *a, unsigned char *b)
+{
+ /* If we know the endianness of this architecture, and we're using
+ 32-bit fp_digits, we can optimize this */
+#if (defined(ENDIAN_LITTLE) || defined(ENDIAN_BIG)) && !defined(FP_64BIT)
+ /* But not for both simultaneously */
+#if defined(ENDIAN_LITTLE) && defined(ENDIAN_BIG)
+#error Both ENDIAN_LITTLE and ENDIAN_BIG defined.
+#endif
+ {
+ int c = fp_unsigned_bin_size(a);
+ unsigned char *pd = (unsigned char *)a->dp;
+
+ /* read the bytes out */
+#ifdef ENDIAN_BIG
+ {
+ /* Use Duff's device to unroll the loop. */
+ int idx = (c - 1) & ~3;
+ switch (c % 4) {
+ case 0: do { b[idx+0] = *pd++;
+ case 3: b[idx+1] = *pd++;
+ case 2: b[idx+2] = *pd++;
+ case 1: b[idx+3] = *pd++;
+ idx -= 4;
+ } while ((c -= 4) > 0);
+ }
+ }
+#else
+ for (c -= 1; c >= 0; c -= 1) {
+ b[c] = *pd++;
+ }
+#endif
+ }
+#else
+ int x;
+ fp_int t;
+
+ fp_init_copy(&t, a);
+
+ x = 0;
+ while (fp_iszero (&t) == FP_NO) {
+ b[x++] = (unsigned char) (t.dp[0] & 255);
+ fp_div_2d (&t, 8, &t, NULL);
+ }
+ fp_reverse (b, x);
+#endif
+}
+
+/* $Source$ */
+/* $Revision$ */
+/* $Date$ */