implement unsigned -> float casts

amd64 lacks an instruction for this so it has to be implemented with
signed -> float casts:
 - Word casting is done by zero-extending the word to a long and then doing
   a regular signed cast.
 - Long casting is done by dividing by two with correct rounding if the
   highest bit is set and casting that to float, then adding
   1 to mantissa with integer addition

1 files changed, 49 insertions, 0 deletions

diff --git a/test/fpcnv.ssa b/test/fpcnv.ssa
index d9851d8..4dac489 100644
--- a/test/fpcnv.ssa
+++ b/test/fpcnv.ssa
@@ -17,13 +17,62 @@ function d $ftrunc(d %f) {
 	ret %rt
 }
 
+export
+function s $wtos(w %w) {
+@start
+	%rt =s uwtof %w
+	ret %rt
+}
+export
+function d $wtod(w %w) {
+@start
+	%rt =d uwtof %w
+	ret %rt
+}
+
+export
+function s $ltos(l %l) {
+@start
+	%rt =s ultof %l
+	ret %rt
+}
+export
+function d $ltod(l %l) {
+@start
+	%rt =d ultof %l
+	ret %rt
+}
+
 # >>> driver
 # extern float fneg(float);
 # extern double ftrunc(double);
+#
+# extern float wtos(unsigned int);
+# extern double wtod(unsigned int);
+# extern float ltos(long long unsigned int);
+# extern double ltod(long long unsigned int);
+#
+# unsigned long long iin[] = { 0, 1, 16, 234987, 427386245, 0x7fff0000,
+# 	0xffff0000, 23602938196141, 72259248152500195, 9589010795705032704ull,
+# 	0xdcf5fbe299d0148aull, 0xffffffff00000000ull, -1 };
+#
 # int main() {
+# 	int i;
+#
 # 	if (fneg(1.23f) != -1.23f)  return 1;
 # 	if (ftrunc(3.1415) != 3.0)  return 2;
 # 	if (ftrunc(-1.234) != -1.0) return 3;
+#
+# 	for (i=0; i<sizeof(iin)/sizeof(iin[0]); i++) {
+# 		if (wtos(iin[i]) != (float) (unsigned int)iin[i])
+# 			return 4;
+# 		if (wtod(iin[i]) != (double)(unsigned int)iin[i])
+# 			return 5;
+# 		if (ltos(iin[i]) != (float) iin[i])
+# 			return 6;
+# 		if (ltod(iin[i]) != (double)iin[i])
+# 			return 7;
+# 	}
 # 	return 0;
 # }
 # <<<