[Qemu-devel] [PATCH 6/7] tcg: Streamline movcond_i64 using 32-bit arithmetic

[Richard Henderson <rth@twiddle.net>]

Avoiding 64-bit arithmetic (outside of the compare) reduces the
generated op count from 15 to 12, and the generated code size on
i686 from 105 to 88 bytes.

Signed-off-by: Richard Henderson <rth@twiddle.net>
---
 tcg/tcg-op.h | 42 +++++++++++++++++++++++++++++++-----------
 1 file changed, 31 insertions(+), 11 deletions(-)

diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
index 6d28f82..3e375ea 100644
--- a/tcg/tcg-op.h
+++ b/tcg/tcg-op.h
@@ -2141,18 +2141,38 @@ static inline void tcg_gen_movcond_i64(TCGCond cond, TCGv_i64 ret,
                                        TCGv_i64 c1, TCGv_i64 c2,
                                        TCGv_i64 v1, TCGv_i64 v2)
 {
-    if (TCG_TARGET_HAS_movcond_i64) {
-        tcg_gen_op6i_i64(INDEX_op_movcond_i64, ret, c1, c2, v1, v2, cond);
+    if (TCG_TARGET_REG_BITS == 32) {
+        TCGv_i32 t0 = tcg_temp_new_i32();
+        TCGv_i32 t1 = tcg_temp_new_i32();
+        tcg_gen_op6i_i32(INDEX_op_setcond2_i32, t0,
+                         TCGV_LOW(c1), TCGV_HIGH(c1),
+                         TCGV_LOW(c2), TCGV_HIGH(c2), cond);
+        tcg_gen_neg_i32(t0, t0);
+
+        tcg_gen_and_i32(t1, TCGV_LOW(v1), t0);
+        tcg_gen_andc_i32(TCGV_LOW(ret), TCGV_LOW(v2), t0);
+        tcg_gen_or_i32(TCGV_LOW(ret), TCGV_LOW(ret), t1);
+
+        tcg_gen_and_i32(t1, TCGV_HIGH(v1), t0);
+        tcg_gen_andc_i32(TCGV_HIGH(ret), TCGV_HIGH(v2), t0);
+        tcg_gen_or_i32(TCGV_HIGH(ret), TCGV_HIGH(ret), t1);
+
+        tcg_temp_free_i32(t0);
+        tcg_temp_free_i32(t1);
     } else {
-        TCGv_i64 t0 = tcg_temp_new_i64();
-        TCGv_i64 t1 = tcg_temp_new_i64();
-        tcg_gen_setcond_i64(cond, t0, c1, c2);
-        tcg_gen_neg_i64(t0, t0);
-        tcg_gen_and_i64(t1, v1, t0);
-        tcg_gen_andc_i64(ret, v2, t0);
-        tcg_gen_or_i64(ret, ret, t1);
-        tcg_temp_free_i64(t0);
-        tcg_temp_free_i64(t1);
+        if (TCG_TARGET_HAS_movcond_i64) {
+            tcg_gen_op6i_i64(INDEX_op_movcond_i64, ret, c1, c2, v1, v2, cond);
+        } else {
+            TCGv_i64 t0 = tcg_temp_new_i64();
+            TCGv_i64 t1 = tcg_temp_new_i64();
+            tcg_gen_setcond_i64(cond, t0, c1, c2);
+            tcg_gen_neg_i64(t0, t0);
+            tcg_gen_and_i64(t1, v1, t0);
+            tcg_gen_andc_i64(ret, v2, t0);
+            tcg_gen_or_i64(ret, ret, t1);
+            tcg_temp_free_i64(t0);
+            tcg_temp_free_i64(t1);
+        }
     }
 }
 
-- 
1.7.11.4