Created softfloat_demo showcasing how to do math with SoftFloat

.gitignore

@@ -52,6 +52,8 @@ examples/asm/sumtest/sumtest
 examples/asm/example/example
 examples/C/sum/sum
 examples/C/fir/fir
+examples/fp/softfloat_demo/softfloat_demo
+pipelined/src/fma/fma16_testgen
 linux/devicetree/debug/*
 !linux/devicetree/debug/dump-dts.sh
 linux/testvector-generation/genCheckpoint.gdb

examples/fp/softfloat_demo/Makefile

@@ -0,0 +1,23 @@
+# Makefile
+
+CC     = gcc
+CFLAGS = -O3
+LIBS   = -lm
+LFLAGS = -L. 
+# Link against the riscv-isa-sim version of SoftFloat rather than 
+# the regular version to get RISC-V NaN behavior
+IFLAGS   = -I$(RISCV)/riscv-isa-sim/softfloat
+LIBS   = $(RISCV)/riscv-isa-sim/build/libsoftfloat.a
+#IFLAGS = -I../../../addins/SoftFloat-3e/source/include/
+#LIBS   = ../../../addins/SoftFloat-3e/build/Linux-x86_64-GCC/softfloat.a
+SRCS   = $(wildcard *.c)
+
+PROGS = $(patsubst %.c,%,$(SRCS))
+
+all:	$(PROGS)
+
+%: %.c
+	$(CC) $(CFLAGS) $(IFLAGS) $(LFLAGS) -o $@ $< $(LIBS)
+
+clean: 
+	rm -f $(PROGS)

examples/fp/softfloat_demo/softfloat_demo.c

@@ -0,0 +1,53 @@
+// softfloat_demo.c
+// David_Harris@hmc.edu 27 February 2022
+// 
+// Demonstrate using SoftFloat do compute a floating-point, then print results
+
+#include <stdio.h>
+#include <stdint.h>
+#include "softfloat.h"
+#include "softfloat_types.h"
+typedef union sp {
+  uint32_t v;
+  float f;
+} sp;
+
+void printF32(char *msg, float32_t f) {
+  sp conv;
+  conv.v = f.v; // use union to convert between hexadecimal and floating-point views
+  printf ("%s: 0x%08x = %g\n", msg, conv.v, conv.f);
+}
+
+void printFlags(void) {
+  int NX = softfloat_exceptionFlags % 2;
+  int UF = (softfloat_exceptionFlags >> 1) % 2;
+  int OF = (softfloat_exceptionFlags >> 2) % 2;
+  int DZ = (softfloat_exceptionFlags >> 3) % 2;
+  int NV = (softfloat_exceptionFlags >> 4) % 2;
+  printf ("exceptions: Inexact %d Underflow %d Overflow %d DivideZero %d Invalid %d\n", 
+          NX, UF, OF, DZ, NV);
+}
+
+void softfloatInit(void) {
+    // rounding modes: RNE: softfloat_round_near_even
+    //                 RZ:  softfloat_round_minMag
+    //                 RP:  softfloat_round_max
+    //                 RM:  softfloat_round_min
+    softfloat_roundingMode = softfloat_round_near_even; 
+    softfloat_exceptionFlags = 0; // clear exceptions
+    softfloat_detectTininess = softfloat_tininess_beforeRounding; // RISC-V behavior for tininess
+}
+
+int main()
+{
+    float32_t x, y, z, r;
+
+    x.v = 0x3fc00000;
+    y.v = 0x3fc00000;
+    z.v = 0x00000001;
+
+    softfloatInit(); 
+    r = f32_mulAdd(x, y, z);
+    printF32("X", x); printF32("Y", y); printF32("Z", z);
+    printF32("result = X*Y+Z", r); printFlags();
+}

pipelined/src/fma/div.c

@@ -1,52 +0,0 @@
-#include <stdio.h>
-#include <stdint.h>
-#include "softfloat.h"
-#include "softfloat_types.h"
-
-int float_rounding_mode = 0;
-
-union dp {
-  unsigned short x[4];
-  double y;
-} X;
-
-
-int main()
-{
-    uint8_t rounding_mode;
-    uint8_t exceptions;
-
-    uint64_t n, d, result;
-    float64_t   d_n, d_d, d_result;
-
-    n = 0x3feffffffefffff6;
-    d = 0xffeffffffffffffe;
-    //n = 0x00000000400001ff;
-    //d = 0x3ffffdfffffffbfe;    
-
-    d_n.v = n;
-    d_d.v = d;
-
-    softfloat_roundingMode = rounding_mode;
-    softfloat_exceptionFlags = 0;
-    softfloat_detectTininess = softfloat_tininess_beforeRounding;
-
-    d_result = f64_div(d_n, d_d);
-
-    //result = d_result.v;    
-    //exceptions = softfloat_exceptionFlags & 0x1f;
-
-    X.x[3] = (d_result.v & 0xffff000000000000) >> 48;
-    X.x[2] = (d_result.v & 0x0000ffff00000000) >> 32;    
-    X.x[1] = (d_result.v & 0x00000000ffff0000) >> 16;
-    X.x[0] = (d_result.v & 0x000000000000ffff);
-
-    printf("Number = %.4x\n", X.x[3]);
-    printf("Number = %.4x\n", X.x[2]);
-    printf("Number = %.4x\n", X.x[1]);
-    printf("Number = %.4x\n", X.x[0]);
-    printf("Number = %1.25lg\n", X.y);    
-    
-
-    return 0;
-}

pipelined/src/fma/fma32.c

@@ -1,47 +0,0 @@
-#include <stdio.h>
-#include <stdint.h>
-#include "softfloat.h"
-#include "softfloat_types.h"
-
-int float_rounding_mode = 0;
-
-union sp {
-  unsigned short x[2];
-  float y;
-} X;
-
-
-int main()
-{
-    uint8_t rounding_mode;
-    uint8_t exceptions;
-
-    uint32_t multiplier, multiplicand, addend, result;
-    float32_t f_multiplier, f_multiplicand, f_addend, f_result;
-
-    multiplier = 0xbf800000;
-    multiplicand = 0xbf800000;
-    addend = 0xffaaaaaa;
-
-    f_multiplier.v = multiplier;
-    f_multiplicand.v = multiplicand;
-    f_addend.v = addend;
-
-    softfloat_roundingMode = rounding_mode;
-    softfloat_exceptionFlags = 0;
-    softfloat_detectTininess = softfloat_tininess_beforeRounding;
-
-    f_result = f32_mulAdd(f_multiplier, f_multiplicand, f_addend);
-
-    result = f_result.v;    
-    exceptions = softfloat_exceptionFlags & 0x1f;
-
-    printf("%x\n", f_result.v);
-
-    // Print out SP number
-    X.x[1] = (f_result.v & 0xffff0000) >> 16;
-    X.x[0] = (f_result.v & 0x0000ffff);
-    printf("Number = %f\n", X.y);
-
-    return 0;
-}