Unwanted partial constant propagation in 64-bit integer arguments to builtins

Here are two examples that cause an internal error in Asmexpand.ml:

volatile long long x; void f(unsigned int i) { x = i; }

unsigned g(unsigned i) { return __builtin_clzll(i); }

The argument "i" to builtin volatile store or __builtin_clzll is turned into a BA_splitlong(BA_int 0, BA <variable i>), which Asmexpand.ml doesn't know how to handle.

The fix (in AST.builtin_arg_ok) is to prevent this 'optimization' for all builtins except those of the "OK_all" kind, i.e. __builtin_annot.

Regression tests were added and tested on IA32.  Need to retest on ARM and PowerPC.

1 files changed, 3 insertions, 0 deletions

diff --git a/test/regression/builtins-powerpc.c b/test/regression/builtins-powerpc.c
index 1d220c11..23e9d191 100644
--- a/test/regression/builtins-powerpc.c
+++ b/test/regression/builtins-powerpc.c
@@ -14,6 +14,7 @@ int main(int argc, char ** argv)
   unsigned int x = 0x12345678;
   unsigned int y = 0xDEADBEEF;
   unsigned long long xx = 0x1234567812345678ULL;
+  unsigned z;
   double a = 3.14159;
   double b = 2.718;
   double c = 1.414;
@@ -24,6 +25,8 @@ int main(int argc, char ** argv)
   printf("clz(%x) = %d\n", x, __builtin_clz(x));
   printf("clzll(%llx) = %d\n", (unsigned long long) x, __builtin_clzll(x));
   printf("clzll(%llx) = %d\n", xx, __builtin_clzll(xx));
+  z = __builtin_bswap(x);
+  printf("clzll(%lx) = %d\n", z, __builtin_clzll(z));
   printf("bswap(%x) = %x\n", x, __builtin_bswap(x));
   printf("bswap16(%x) = %x\n", s, __builtin_bswap16(s));