target-i386: SSE4.2: fix pcmpXstri instructions

ffs1 returns the first bit set to one starting counting from the most
significant bit.

pcmpXstri returns the most significant bit set to one, starting counting
from the least significant bit.

Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

diff --git a/target-i386/ops_sse.h b/target-i386/ops_sse.h
index 0136df934512a8d33ba9c61e4021920f55f45485..0667c879ca68bda6a44364e4f9077ad3195545b5 100644 (file)
--- a/target-i386/ops_sse.h
+++ b/target-i386/ops_sse.h
@@ -2099,7 +2099,7 @@ void glue(helper_pcmpestri, SUFFIX)(CPUX86State *env, Reg *d, Reg *s,
                                  pcmp_elen(env, R_EAX, ctrl));
 
     if (res) {
-        env->regs[R_ECX] = ((ctrl & (1 << 6)) ? rffs1 : ffs1)(res) - 1;
+        env->regs[R_ECX] = (ctrl & (1 << 6)) ? rffs1(res) - 1 : 32 - ffs1(res);
     } else {
         env->regs[R_ECX] = 16 >> (ctrl & (1 << 0));
     }
@@ -2137,7 +2137,7 @@ void glue(helper_pcmpistri, SUFFIX)(CPUX86State *env, Reg *d, Reg *s,
                                  pcmp_ilen(d, ctrl));
 
     if (res) {
-        env->regs[R_ECX] = ((ctrl & (1 << 6)) ? rffs1 : ffs1)(res) - 1;
+        env->regs[R_ECX] = (ctrl & (1 << 6)) ? rffs1(res) - 1 : 32 - ffs1(res);
     } else {
         env->regs[R_ECX] = 16 >> (ctrl & (1 << 0));
     }