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/volatile2.c b/test/regression/volatile2.c
index 3bad6ae2..bd2a93a3 100644
--- a/test/regression/volatile2.c
+++ b/test/regression/volatile2.c
@@ -13,6 +13,7 @@ unsigned char guc;
 signed short gss;
 unsigned short gus;
 int gi;
+unsigned gu;
 float gf;
 double gd;
 long long gll;
@@ -44,6 +45,8 @@ int main()
   TEST("global float", float, gf, 0.5, 256.0);
   TEST("global double", double, gd, 3.1415, 2.718);
   TEST("global long long", long long, gll, 0x123456789ABCDEFLL, 0x789ABCDEF1234567LL);
+  /* Test for unwanted partial constant propagation */
+  *((volatile long long *) &gll) = gu;
   return 0;
 }