TCG: Use x86-64 zero extension instructions.

Signed-off-by: Paul Brook <paul@codesourcery.com>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5180 c046a42c-6fe2-441c-8c8c-71466251a162

diff --git a/tcg/x86_64/tcg-target.c b/tcg/x86_64/tcg-target.c
index 38e164e..304a0c3 100644 (file)
--- a/tcg/x86_64/tcg-target.c
+++ b/tcg/x86_64/tcg-target.c
@@ -382,6 +382,12 @@ static inline void tgen_arithi32(TCGContext *s, int c, int r0, int32_t val)
     if (val == (int8_t)val) {
         tcg_out_modrm(s, 0x83, c, r0);
         tcg_out8(s, val);
+    } else if (c == ARITH_AND && val == 0xffu) {
+        /* movzbl */
+        tcg_out_modrm(s, 0xb6 | P_EXT | P_REXB, r0, r0);
+    } else if (c == ARITH_AND && val == 0xffffu) {
+        /* movzwl */
+        tcg_out_modrm(s, 0xb7 | P_EXT, r0, r0);
     } else {
         tcg_out_modrm(s, 0x81, c, r0);
         tcg_out32(s, val);
@@ -393,6 +399,15 @@ static inline void tgen_arithi64(TCGContext *s, int c, int r0, int64_t val)
     if (val == (int8_t)val) {
         tcg_out_modrm(s, 0x83 | P_REXW, c, r0);
         tcg_out8(s, val);
+    } else if (c == ARITH_AND && val == 0xffu) {
+        /* movzbl */
+        tcg_out_modrm(s, 0xb6 | P_EXT | P_REXW, r0, r0);
+    } else if (c == ARITH_AND && val == 0xffffu) {
+        /* movzwl */
+        tcg_out_modrm(s, 0xb7 | P_EXT | P_REXW, r0, r0);
+    } else if (c == ARITH_AND && val == 0xffffffffu) {
+        /* 32-bit mov zero extends */
+        tcg_out_modrm(s, 0x8b, r0, r0);
     } else if (val == (int32_t)val) {
         tcg_out_modrm(s, 0x81 | P_REXW, c, r0);
         tcg_out32(s, val);