From ce42e30513750e5fad89e73888fc836409260d4e Mon Sep 17 00:00:00 2001
From: Jeff Wang <jeff.wang@utexas.edu>
Date: Fri, 4 Oct 2019 23:49:42 -0400
Subject: [PATCH] log10() fixes to prevent calculator from crashing

---
 src/decn/decn.c           | 10 +++++-----
 src/decn/decn.h           |  8 +++++++-
 src/decn/decn_test.c      | 21 +++++++++++++++++++++
 src/decn/proto/ln_mfp.cpp | 11 ++++-------
 4 files changed, 37 insertions(+), 13 deletions(-)

diff --git a/src/decn/decn.c b/src/decn/decn.c
index 068808d..a511237 100644
--- a/src/decn/decn.c
+++ b/src/decn/decn.c
@@ -1015,11 +1015,11 @@ void ln_decn(void){
 #undef NUM_A_ARR
 }
 
-void log10_decn(void){
-	ln_decn();
-	copy_decn(&BDecn, &DECN_LN_10);
-	div_decn();
-}
+//inline void log10_decn(void){
+//	ln_decn();
+//	copy_decn(&BDecn, &DECN_LN_10);
+//	div_decn();
+//}
 
 static void set_str_error(void){
 	Buf[0] = 'E';
diff --git a/src/decn/decn.h b/src/decn/decn.h
index fa45ec5..c7367b2 100644
--- a/src/decn/decn.h
+++ b/src/decn/decn.h
@@ -69,7 +69,13 @@ void mult_decn(void);
 void div_decn(void);
 
 void ln_decn(void);
-void log10_decn(void);
+//inline void log10_decn(void);
+#define log10_decn() do {               \
+		ln_decn();                      \
+		copy_decn(&BDecn, &DECN_LN_10); \
+		div_decn();                     \
+	} while(0);
+
 
 //Buf should hold at least 18 + 4 + 5 + 1 = 28
 #define DECN_BUF_SIZE 28
diff --git a/src/decn/decn_test.c b/src/decn/decn_test.c
index 772eb92..48a1ff2 100644
--- a/src/decn/decn_test.c
+++ b/src/decn/decn_test.c
@@ -62,6 +62,22 @@ static void log_test(
 	printf("     : %s\n\n", Buf);
 }
 
+static void log10_test(
+	const char* x_str, int x_exp,
+	const char* res_str, int res_exp)
+{
+	build_dec80(x_str, x_exp);
+	decn_to_str_complete(&AccDecn);
+	printf("  a  : %s\n", Buf);
+	log10_decn();
+	decn_to_str_complete(&AccDecn);
+	printf("ln(a): %s\n", Buf);
+	build_decn_at(&diff, res_str, res_exp);
+	take_diff();
+	decn_to_str_complete(&diff);
+	printf("     : %s\n\n", Buf);
+}
+
 int main(void){
 //	dec80 acc, b;
 
@@ -226,5 +242,10 @@ int main(void){
 		"-22.3227534185273434", 0
 	);
 
+	//new acc for log test
+	log10_test(
+		"1.5", 0,
+		"0.176091259", 0
+	);
 	return 0;
 }
diff --git a/src/decn/proto/ln_mfp.cpp b/src/decn/proto/ln_mfp.cpp
index 033ebb1..6d63b58 100644
--- a/src/decn/proto/ln_mfp.cpp
+++ b/src/decn/proto/ln_mfp.cpp
@@ -10,10 +10,6 @@ using namespace boost::multiprecision;
 using std::cout;
 using std::endl;
 
-static const int BSIZE = 200;
-char buf[BSIZE];
-char pbuf[BSIZE];
-
 static const int NUM_A_ARR = 9;
 mpfr_float a_arr[NUM_A_ARR];
 mpfr_float ln_a_arr[NUM_A_ARR];
@@ -48,7 +44,7 @@ int main(void){
 		mpfr_float accum(b_j, CALC_PRECISION);
 		mpfr_float_1000 actual;
 		actual = log(A);
-		
+
 		int num_times[NUM_A_ARR];
 		//track number of times multiplied by a_arr[j]
 		for (int j = 0; j < NUM_A_ARR; j++){
@@ -69,7 +65,7 @@ int main(void){
 // 			printf("  %d: num_times: %d, ", j, num_times[j]);
 // 			cout << b_j << endl;
 		}
-		
+
 		//build final value
 		accum = b_j; //remainder
 		accum *= pow(10.0, -(NUM_A_ARR - 1)); //scale remainder
@@ -81,10 +77,11 @@ int main(void){
 		}
 		accum = -accum;
 
+		//calculate relative error
 		mpfr_float_1000 calc, diff;
 		calc = accum;
 		diff = (actual - calc)/actual;
-		
+
 		if (diff > 5e-17){
 			cout << x << ": ";
 			cout << std::setprecision(18) << accum << ", ";