x86: fix issue with casting in Cvtf2i

UBSAN flags this operation because it detects that arg is being cast directly
to an unsigned type, argBits. this patch fixes this by first casting the
value to a signed int type, then reintrepreting the raw bits of the signed
int into argBits.

diff --git a/src/arch/x86/isa/microops/mediaop.isa b/src/arch/x86/isa/microops/mediaop.isa
index cdb3b4899541300dd9ec0fd890f9a5713982061a..63e22a23f51c4d3ffe21d48a6469cbc9d7eec253 100644 (file)
--- a/src/arch/x86/isa/microops/mediaop.isa
+++ b/src/arch/x86/isa/microops/mediaop.isa
@@ -1220,9 +1220,11 @@ let {{
                 }
 
                 if (destSize == 4) {
-                    argBits = (uint32_t)arg;
+                    int32_t i_arg = (int32_t)arg;
+                    argBits = *((uint32_t*)&i_arg);
                 } else {
-                    argBits = (uint64_t)arg;
+                    int64_t i_arg = (int64_t)arg;
+                    argBits = *((uint64_t*)&i_arg);
                 }
                 int destHiIndex = destStart + (i + 1) * destSizeBits - 1;
                 int destLoIndex = destStart + (i + 0) * destSizeBits;