[gcc(refs/users/aoliva/heads/testbase)] Test case for PR rtl-optimization/60473

[gcc(refs/users/aoliva/heads/testbase)] Test case for PR rtl-optimization/60473

[Alexandre Oliva]

https://gcc.gnu.org/g:76eafcc395d2bcd4147cb1ba1a8aff321571402f

commit 76eafcc395d2bcd4147cb1ba1a8aff321571402f
Author: Roger Sayle <roger@nextmovesoftware.com>
Date:   Tue Aug 4 16:56:06 2020 +0100

    Test case for PR rtl-optimization/60473
    
    PR rtl-optimization/60473 is code quality regression that has
    been cured by improvements to register allocation.  For the function
    in the test case, GCC 4.4, 4.5 and 4.6 generated very poor code
    requiring two mov instructions, and GCC 4.7 and 4.8 (when the PR was
    filed) produced better but still poor code with one mov instruction.
    Since GCC 4.9 (including current mainline), it generates optimal
    code with no mov instructions, matching what used to be generated
    in GCC 4.1.
    
    2020-08-04  Roger Sayle  <roger@nextmovesoftware.com>
    
    gcc/testsuite/ChangeLog
            PR rtl-optimization/60473
            * gcc.target/i386/pr60473.c: New test.

Diff:
---
 gcc/testsuite/gcc.target/i386/pr60473.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/gcc/testsuite/gcc.target/i386/pr60473.c b/gcc/testsuite/gcc.target/i386/pr60473.c
new file mode 100644
index 00000000000..d81962e7b67
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr60473.c
@@ -0,0 +1,12 @@
+/* PR rtl-optimization/60473  */
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2" } */
+
+unsigned long long foo()
+{
+  unsigned long long h,l;
+  asm volatile ("rdtsc": "=a" (l), "=d" (h));
+  return l | (h << 32);
+}
+
+/* { dg-final { scan-assembler-not "mov" } } */