From 33613a85afc4b1481367fbe92a17ee59c240250b Mon Sep 17 00:00:00 2001
From: Sven Eisenhauer <sven@sven-eisenhauer.net>
Date: Fri, 10 Nov 2023 15:11:48 +0100
Subject: add new repo

---
 .../Public-Key-Algorithmen/PKA-Prakt1/src/main.c   | 88 ++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 Master/Public-Key-Algorithmen/PKA-Prakt1/src/main.c

(limited to 'Master/Public-Key-Algorithmen/PKA-Prakt1/src/main.c')

diff --git a/Master/Public-Key-Algorithmen/PKA-Prakt1/src/main.c b/Master/Public-Key-Algorithmen/PKA-Prakt1/src/main.c
new file mode 100644
index 0000000..2987966
--- /dev/null
+++ b/Master/Public-Key-Algorithmen/PKA-Prakt1/src/main.c
@@ -0,0 +1,88 @@
+/*
+ * main.c
+ *
+ *  Created on: 23.04.2010
+ *      Author: sven
+ */
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <time.h>
+#include <sys/time.h>
+
+#define HI(x) (x >> 16)
+#define LO(x) (x & 0x0000FFFF)
+
+void mulc(uint32_t *u, uint32_t *v, uint32_t a, uint32_t b)
+{
+	uint32_t t;
+	t = LO(a) * LO(b);
+	*v = LO(t);
+	t = HI(t) + HI(a) * LO(b);
+	*u = HI(t);
+	t = LO(t) + LO(a) * HI(b);
+	*v |= LO(t) << 16;
+	*u += HI(t) + HI(a) * HI(b);
+}
+void mula(uint32_t *u, uint32_t *v, uint32_t a, uint32_t b)
+{
+	asm
+	(
+			"mov %2,%%eax\n"
+			"mul %3\n"
+			"mov %%edx, %0\n"
+			"mov %%eax, %1"
+			:"=r"(*u),"=r"(*v)
+			:"r"(a),"r"(b)
+	);
+}
+void initRandomizer()
+{
+	srand(time(NULL));
+}
+uint32_t getRandomUint32()
+{
+	uint32_t res = rand();
+	if(res % 2)
+	{
+		return (res | 1<<31);
+	}
+	return res;
+}
+int main(int argc, char* argv[])
+{
+	initRandomizer();
+	uint32_t a = getRandomUint32();
+	uint32_t b = getRandomUint32();
+	uint32_t u,v;
+	uint32_t counter;
+	uint32_t outerCnt;
+	const uint32_t NUM_INNER_LOOPS = 1000000;
+	const uint32_t NUM_OUTER_LOOPS = 1000;
+	struct timeval startc;
+	struct timeval endc;
+	struct timeval starta;
+	struct timeval enda;
+	long diffCsum = 0,diffAsum = 0;
+	for(outerCnt=0;outerCnt<NUM_OUTER_LOOPS;outerCnt++) {
+		gettimeofday(&startc,0);
+		for (counter=0; counter < NUM_INNER_LOOPS; counter++) {
+			mulc(&u,&v,a,b);
+		}
+		gettimeofday(&endc,0);
+		diffCsum += (endc.tv_sec*1000000 + endc.tv_usec) - (startc.tv_sec*1000000 + startc.tv_usec);
+		printf("C %u * %u = %u.%u\n",a,b,u,v);
+		u=0;
+		v=0;
+		gettimeofday(&starta,0);
+		for (counter=0; counter < NUM_INNER_LOOPS; counter++) {
+			mula(&u,&v,a,b);
+		}
+		gettimeofday(&enda,0);
+		diffAsum += (enda.tv_sec*1000000 + enda.tv_usec) - (starta.tv_sec*1000000 + starta.tv_usec);
+		printf("ASM %u * %u = %u.%u\n",a,b,u,v);
+	}
+	printf("C: total %ld usec, avg %ld usec\n",diffCsum,(diffCsum / NUM_OUTER_LOOPS));
+	printf("ASM: total %ld usec, avg %ld usec\n",diffAsum,(diffAsum / NUM_OUTER_LOOPS));
+	return EXIT_SUCCESS;
+}
-- 
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