Merge branch 'main' of https://github.com/davidharrishmc/riscv-wally into main

pipelined/src/fma/Makefile

@@ -0,0 +1,10 @@
+TARGET ?= fma
+
+# for some reason, softfloat.a needs to be symlinked to the local directory.  -L isn't working
+$(TARGET): $(TARGET).c Makefile
+	gcc -O2 -o $(TARGET) $(TARGET).c softfloat.a  \
+		 -I../../../addins/SoftFloat-3e/source/include  \
+		 -L../../../addins/SoftFloat-3e/build/Linux-x86_64-GCC 
+
+clean: 
+	rm $(TARGET)

pipelined/src/fma/div.c

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+#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/fma.c

@@ -0,0 +1,47 @@
+#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;
+}

pipelined/src/fma/fma16.sv

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+// fma16.sv
+// David_Harris@hmc.edu 26 February 2022
+// 16-bit floating-point multiply-accumulate
+
+// Operation: general purpose multiply, add, fma, with optional negation
+//   If mul=1, p = x * y.  Else p = x.
+//   If add=1, result = p + z.  Else result = p.
+//   If negp or negz = 1, negate p or z to handle negations and subtractions
+//   fadd: mul = 0, add = 1, negp = negz = 0
+//   fsub: mul = 0, add = 1, negp = 0, negz = 1
+//   fmul: mul = 1, add = 0, negp = 0, negz = 0
+//   fma:  mul = 1, add = 1, negp = 0, negz = 0
+
+module fma16(
+  input  logic [15:0] x, y, z,
+  input  logic        add, mul, negp, negz,
+  input  logic [1:0]  roundmode,  // 00: rz, 01: rne, 10: rp, 11: rn
+  output logic [15:0] result);
+ 
+  logic [10:0] xm, ym, zm;
+  logic [4:0] xe, ye, ze;
+  logic       xs, ys, zs;
+  logic       zs1; // sign before optional negation
+  logic       ps;  // sign of product
+
+  unpack unpack(x, y, z, xm, ym, zm, xe, ye, ze, xs, ys, zs1);  // unpack inputs
+  signadj signadj(negp, negz, xs, ys, zs1, ps, zs);             // handle negations
+  mult mult(mul, xm, ym, xe, ye, pm, pe);                       // p = x * y
+  add add(add, pm, zm, pe, ze, ps, zs, rm, re, rs);             // r = z + p
+  postproc post(roundmode, rm, re, rs, result);                 // normalize, round, pack
+endmodule
+
+module mult(
+  input  logic        mul,
+  input  logic [10:0] xm, ym,
+  input  logic [4:0]  xe, ye,
+  input  logic        xs, ys,
+  output logic [21:0] pm,
+  output logic [5:0]  pe);
+
+  // only multiply if mul = 1
+  assign pm = mul ? xm * ym : xm;       // multiply mantiassas 
+  assign pe = mul ? xe + ye : xe;  
+endmodule
+
+module add(
+  input  logic        add,
+  input  logic [21:0] pm, 
+  input  logic [10:0] zm,
+  input  logic [5:0]  pe, 
+  input  logic [4:0]  ze,
+  input  logic        ps, zs,
+  output logic [22:0] rm,
+  output logic [6:0]  re,
+  output logic        rs);
+
+  logic [22:0] arm;
+  logic [6:0]  are;
+  logic        ars;
+
+  alignshift as(pe, ze, zm, zmaligned);
+  condneg cnp(pm, ps, pmn);
+  condneg cnz(zm, zs, zmn);
+  
+  // add or pass product through
+  assign rm = add ? arm : pm;
+  assign re = add ? are : pe;
+  assign rs = add ? ars : ps;
+);
+
+module postproc(
+  input  logic [1:0] roundmode,
+  input  logic [22:0] rm,
+  input  logic [6:0]  re,
+  input  logic        rs,
+  output logic [15:0] result);
+
+  // add special case handling for zeros, NaN, Infinity
+endmodule
+
+module signadj(
+  input  logic negx, negz,
+  input  logic xs, ys, zs1,
+  output logic ps, zs);
+
+  assign ps = xs ^ ys ^ negx; // sign of product
+  assign zs = zs1 ^ negz; // 
+endmodule
+
+module unpack(
+  input  logic [15:0] x, y, z,
+  output logic [10:0] xm, ym, zm,
+  output logic [4:0]  xe, ye, ze,
+  output logic        xs, ys, zs);
+
+  unpacknum upx(x, xm, xe, xs);
+  unpacknum upy(y, ym, ye, ys);
+  unpacknum upz(z, zm, ze, zs);
+endmodule
+
+module unpacknum(
+  input logic  [15:0] num,
+  output logic [10:0] m,
+  output logic [4:0]  e,
+  output logic        s);
+
+  logic [9:0] f;  // fraction without leading 1
+  logic [4:0] eb; // biased exponent
+
+  assign {f, eb, s} = num; // pull bit fields out of floating-point number
+  assign m = {1'b1, f}; // prepend leading 1 to fraction
+  assign e = eb - 15;   // remove bias from exponent
+endmodule
+
+
+// Tests:
+// Every permutation for x, y, z of 
+//    mantissa = {1.0, 1.0000000001, 1.1, 1.1111111110, 1.1111111111}
+//    biased exponent = {1, 2, 14, 15, 16, 21, 29, 30}
+//    sign = {0, 1}
+//    special case: [normal, 0, INF, NaN]

pipelined/src/fma/fma16_testgen.py

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+#!/usr/bin/python3
+
+# fma16_testgen.py
+# David_Harris@hmc.edu 26 February 2022
+# Generate test cases for 16-bit FMA 
+  
+def makeVal(val):
+
+def makeCase(x, y, z, mul, add, msg):
+    xval = makeVal(x);
+    yval = makeVal(y);
+    zval = makeVal(z);
+    mode = mul*2+add; # convert to hexadecimal code
+    expected = makeExpected(x, y, z, mul, add);
+    print(xval,"_", yval, "_", zval, "_", mode, "_", expected, " //", msg);
+
+def makeMulCase(x, y, msg):
+  makeCase(x, y, "0", 1, 0, msg)
+
+################################
+## Main program
+################################
+
+# Directed cases
+makeMulCase("1", "1", "1 x 1");
+
+
+# Corner cases
+
+# Random cases
+

pipelined/src/fma/softfloat.a

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+../../../addins/SoftFloat-3e/build/Linux-x86_64-GCC/softfloat.a