feat(riscv): implement most of the F and D extensions

Author: arromanoff

test/integration/doubles-mixed.c

@@ -1,7 +1,6 @@
 // RUN: %config-gen-path/config-gen.rb --march rv64imfd \
 // RUN:   --template-dir %config-gen-path/templates -o %t.yaml
 // RUN: riscv64-unknown-linux-gnu-clang %s -O2 -c -o %t.out -march=rv64imfd
-// -nostdlib -static
 // RUN: %bin/llvm-bleach %t.out --instructions %t.yaml -o %t.ll \
 // RUN:   --state-struct-file=%t.state.h
 // RUN: sed 's|STATE|%t.state.h|g' %S/inputs/doubles-mixed-main.c > %t.main.c

test/integration/inputs/riscv-mixed-fp.c

@@ -0,0 +1,47 @@
+#include <STATE>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+
+struct register_state regs = {};
+
+int64_t bitcast_to_int(double v) {
+  int64_t res;
+  memcpy(&res, &v, sizeof(double));
+  return res;
+}
+
+double bitcast_to_double(int64_t v) {
+  double res;
+  memcpy(&res, &v, sizeof(double));
+  return res;
+}
+
+// This should be in sync with test/integration/riscv-mixed-fp.c
+// TODO: automate this
+double ref_calc2(double prod, double sum, int x) {
+  return prod + sum - (double)x;
+}
+
+double ref_calc1(double a, double b, int x) {
+  return ref_calc2(a * b, (a + b), x);
+}
+
+double reference(double a, double b, int x) { return ref_calc1(a, b, x); }
+
+int main() {
+  printf("Hello from main\n");
+  // random values
+  double arg_1 = 34.33;
+  double arg_2 = 0.0003344;
+  int arg_3 = 5;
+  regs.FPR[10] = bitcast_to_int(arg_1);
+  regs.FPR[11] = bitcast_to_int(arg_2);
+  regs.GPR[10] = arg_3;
+  top_small(&regs);
+  double res1 = reference(arg_1, arg_2, arg_3);
+  double res2 = bitcast_to_double(regs.FPR[10]);
+  printf("result: %lf\n", res2);
+  printf("reference: %lf\n", res1);
+  return res1 - res2 > 0.1;
+}

test/integration/riscv-mixed-fp.c

@@ -0,0 +1,14 @@
+// RUN: %config-gen-path/config-gen.rb --march rv64imfd \
+// RUN:   --template-dir %config-gen-path/templates -o %t.yaml
+// RUN: riscv64-unknown-linux-gnu-clang %s -O2 -c -o %t.out -march=rv64imfd
+// RUN: %bin/llvm-bleach %t.out --instructions %t.yaml -o %t.ll \
+// RUN:   --state-struct-file=%t.state.h
+// RUN: sed 's|STATE|%t.state.h|g' %S/inputs/riscv-mixed-fp.c > %t.main.c
+// RUN: clang %t.main.c %t.ll -o %t.native.out -g -fsanitize=address,undefined
+// RUN: %t.native.out
+
+double calc2(double prod, double sum, int x) { return prod + sum - (double)x; }
+
+double calc1(double a, double b, int x) { return calc2(a * b, (a + b), x); }
+
+double top_small(double a, double b, int x) { return calc1(a, b, x); }