[Qemu-devel] [PATCH 03/10] target-i386: SSE4.2: fix pcmpXstri instructions

[Aurelien Jarno]

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.

Signed-off-by: Aurelien Jarno <address@hidden>
---
 target-i386/ops_sse.h |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/target-i386/ops_sse.h b/target-i386/ops_sse.h
index 0136df9..0667c87 100644
--- 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));
     }
-- 
1.7.10.4