From f077d16c20c524d7db8cb38a9193242eeade343d Mon Sep 17 00:00:00 2001
From: grischka <grischka>
Date: Fri, 14 Oct 2016 10:44:57 +0200
Subject: [PATCH] tccgen: gen_cast: cast FLOAT to DOUBLE

... to avoid precision loss when casting to int,
also when saving FLOATs to stack
---
 tccgen.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tccgen.c b/tccgen.c
index 70e6fb6..2804539 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -811,6 +811,10 @@ ST_FUNC void save_reg_upstack(int r, int n)
 #else
                     type = &int_type;
 #endif
+                if ((type->t & VT_BTYPE) == VT_FLOAT) {
+                    /* cast to DOUBLE to avoid precision loss */
+                    type->t = (type->t & ~VT_BTYPE) | VT_DOUBLE;
+                }
                 size = type_size(type, &align);
                 loc = (loc - size) & -align;
                 sv.type.t = type->t;
@@ -2349,6 +2353,11 @@ static void gen_cast(CType *type)
                      vpushi(0);
                      gen_op(TOK_NE);
                 } else {
+                    if (sbt == VT_FLOAT) {
+                        /* cast to DOUBLE to avoid precision loss */
+                        gen_cvt_ftof(VT_DOUBLE);
+                        vtop->type.t = (vtop->type.t & ~VT_BTYPE) | VT_DOUBLE;
+                    }
                     /* we handle char/short/etc... with generic code */
                     if (dbt != (VT_INT | VT_UNSIGNED) &&
                         dbt != (VT_LLONG | VT_UNSIGNED) &&