gcc PR 89877: miscompilation due to missing cc clobber in longlong.h macros

simple test such as below was failing.

| void main(int argc, char *argv[])
| {
|    size_t total_time = 115424;                       // expected 115.424
|    double secs = (double)total_time/(double)1000;
|    printf("%s %d %lf\n", "secs", total_time, secs);  // prints 113.504
|    printf("%d\n", (size_t)secs);
| }

The printf eventually called into glibc stdlib/divrem.c:__mpn_divrem()
which uses the __arc__ specific inline asm macros from longlong.h which
were causing miscompilation.

include/
2019-03-28  Vineet Gupta <vgupta@synopsys.com>

	PR 89877

	* longlong.h [__arc__] (add_ssaaaa): Add cc clobber
	(sub_ddmmss): Likewise.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/stdlib/longlong.h b/stdlib/longlong.h
index ee4aac1bb5a075faabf5c4a8d35910a606ee1d3e..638b7894d48c15e54006a452e9accfd164f66e4b 100644 (file)
--- a/stdlib/longlong.h
+++ b/stdlib/longlong.h
@@ -199,7 +199,8 @@ extern UDItype __udiv_qrnnd (UDItype *, UDItype, UDItype, UDItype);
           : "%r" ((USItype) (ah)),                                     \
             "rICal" ((USItype) (bh)),                                  \
             "%r" ((USItype) (al)),                                     \
-            "rICal" ((USItype) (bl)))
+            "rICal" ((USItype) (bl))                                   \
+          : "cc")
 #define sub_ddmmss(sh, sl, ah, al, bh, bl) \
   __asm__ ("sub.f      %1, %4, %5\n\tsbc       %0, %2, %3"             \
           : "=r" ((USItype) (sh)),                                     \
@@ -207,7 +208,8 @@ extern UDItype __udiv_qrnnd (UDItype *, UDItype, UDItype, UDItype);
           : "r" ((USItype) (ah)),                                      \
             "rICal" ((USItype) (bh)),                                  \
             "r" ((USItype) (al)),                                      \
-            "rICal" ((USItype) (bl)))
+            "rICal" ((USItype) (bl))                                   \
+          : "cc")
 
 #define __umulsidi3(u,v) ((UDItype)(USItype)u*(USItype)v)
 #ifdef __ARC_NORM__