===================================================================
@@ -3049,10 +3049,10 @@
(define_insn "*zero_extendsidi2"
[(set (match_operand:DI 0 "nonimmediate_operand"
- "=r,?r,?o,r ,o,?*Ym,?*y,?*Yi,?*x")
+ "=r,?r,?o,r ,o,?*Ym,?!*y,?*Yi,?*x")
(zero_extend:DI
(match_operand:SI 1 "x86_64_zext_operand"
- "0 ,rm,r ,rmWz,0,r ,m ,r ,m")))]
+ "0 ,rm,r ,rmWz,0,r ,m ,r ,m")))]
""
{
switch (get_attr_type (insn))
===================================================================
@@ -0,0 +1,31 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -mtune=athlon64" } */
+
+extern void abort (void);
+
+long double
+__attribute__((noinline, noclone))
+test (float num)
+{
+ unsigned int i;
+
+ if (num < 0.0)
+ num = 0.0;
+
+ __builtin_memcpy (&i, &num, sizeof(unsigned int));
+
+ return (long double)(unsigned long long) i;
+}
+
+int
+main ()
+{
+ long double x;
+
+ x = test (0.0);
+
+ if (x != 0.0)
+ abort ();
+
+ return 0;
+}
Hello! Attached patch fixes PR44578, where MMX register was allocated for zero_extendsidi2 RTX. The patch adds "!" to the interfering alternative, so RA won't choose alternative involving MMX register unless absolute necessary. 2013-04-29 Uros Bizjak <ubizjak@gmail.com> PR target/44578 * config/i386/i386.md (*zero_extendisid2): Add "!" to m->?*y alternative. testsuite/ChangeLog: 2013-04-29 Uros Bizjak <ubizjak@gmail.com> PR target/44578 * gcc.target/i386/pr44578.c: New test. Patch was bootstrapped and regression tested on x86_64-pc-linux-gnu {,-m32} and was committed to mainline SVN. The patch will be backported to 4.7 and 4.8 branches. Uros.