tcg: Add TCG_COND_NEVER, TCG_COND_ALWAYS

There are several cases that can be handled easier inside both
translators and code generators if we have out-of-band values
for conditions.  It's easy enough to handle ALWAYS and NEVER in
the natural way inside the tcg middle-end.

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

1 files changed, 63 insertions, 19 deletions

diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
index bd93fe4f03..551845801d 100644
--- a/tcg/tcg-op.h
+++ b/tcg/tcg-op.h
@@ -646,29 +646,49 @@ static inline void tcg_gen_sari_i32(TCGv_i32 ret, TCGv_i32 arg1, int32_t arg2)
 static inline void tcg_gen_brcond_i32(TCGCond cond, TCGv_i32 arg1,
                                       TCGv_i32 arg2, int label_index)
 {
-    tcg_gen_op4ii_i32(INDEX_op_brcond_i32, arg1, arg2, cond, label_index);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_br(label_index);
+    } else if (cond != TCG_COND_NEVER) {
+        tcg_gen_op4ii_i32(INDEX_op_brcond_i32, arg1, arg2, cond, label_index);
+    }
 }
 
 static inline void tcg_gen_brcondi_i32(TCGCond cond, TCGv_i32 arg1,
                                        int32_t arg2, int label_index)
 {
-    TCGv_i32 t0 = tcg_const_i32(arg2);
-    tcg_gen_brcond_i32(cond, arg1, t0, label_index);
-    tcg_temp_free_i32(t0);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_br(label_index);
+    } else if (cond != TCG_COND_NEVER) {
+        TCGv_i32 t0 = tcg_const_i32(arg2);
+        tcg_gen_brcond_i32(cond, arg1, t0, label_index);
+        tcg_temp_free_i32(t0);
+    }
 }
 
 static inline void tcg_gen_setcond_i32(TCGCond cond, TCGv_i32 ret,
                                        TCGv_i32 arg1, TCGv_i32 arg2)
 {
-    tcg_gen_op4i_i32(INDEX_op_setcond_i32, ret, arg1, arg2, cond);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_movi_i32(ret, 1);
+    } else if (cond == TCG_COND_NEVER) {
+        tcg_gen_movi_i32(ret, 0);
+    } else {
+        tcg_gen_op4i_i32(INDEX_op_setcond_i32, ret, arg1, arg2, cond);
+    }
 }
 
 static inline void tcg_gen_setcondi_i32(TCGCond cond, TCGv_i32 ret,
                                         TCGv_i32 arg1, int32_t arg2)
 {
-    TCGv_i32 t0 = tcg_const_i32(arg2);
-    tcg_gen_setcond_i32(cond, ret, arg1, t0);
-    tcg_temp_free_i32(t0);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_movi_i32(ret, 1);
+    } else if (cond == TCG_COND_NEVER) {
+        tcg_gen_movi_i32(ret, 0);
+    } else {
+        TCGv_i32 t0 = tcg_const_i32(arg2);
+        tcg_gen_setcond_i32(cond, ret, arg1, t0);
+        tcg_temp_free_i32(t0);
+    }
 }
 
 static inline void tcg_gen_mul_i32(TCGv_i32 ret, TCGv_i32 arg1, TCGv_i32 arg2)
@@ -964,17 +984,27 @@ static inline void tcg_gen_sari_i64(TCGv_i64 ret, TCGv_i64 arg1, int64_t arg2)
 static inline void tcg_gen_brcond_i64(TCGCond cond, TCGv_i64 arg1,
                                       TCGv_i64 arg2, int label_index)
 {
-    tcg_gen_op6ii_i32(INDEX_op_brcond2_i32,
-                      TCGV_LOW(arg1), TCGV_HIGH(arg1), TCGV_LOW(arg2),
-                      TCGV_HIGH(arg2), cond, label_index);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_br(label_index);
+    } else if (cond != TCG_COND_NEVER) {
+        tcg_gen_op6ii_i32(INDEX_op_brcond2_i32,
+                          TCGV_LOW(arg1), TCGV_HIGH(arg1), TCGV_LOW(arg2),
+                          TCGV_HIGH(arg2), cond, label_index);
+    }
 }
 
 static inline void tcg_gen_setcond_i64(TCGCond cond, TCGv_i64 ret,
                                        TCGv_i64 arg1, TCGv_i64 arg2)
 {
-    tcg_gen_op6i_i32(INDEX_op_setcond2_i32, TCGV_LOW(ret),
-                     TCGV_LOW(arg1), TCGV_HIGH(arg1),
-                     TCGV_LOW(arg2), TCGV_HIGH(arg2), cond);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_movi_i32(TCGV_LOW(ret), 1);
+    } else if (cond == TCG_COND_NEVER) {
+        tcg_gen_movi_i32(TCGV_LOW(ret), 0);
+    } else {
+        tcg_gen_op6i_i32(INDEX_op_setcond2_i32, TCGV_LOW(ret),
+                         TCGV_LOW(arg1), TCGV_HIGH(arg1),
+                         TCGV_LOW(arg2), TCGV_HIGH(arg2), cond);
+    }
     tcg_gen_movi_i32(TCGV_HIGH(ret), 0);
 }
 
@@ -1273,13 +1303,23 @@ static inline void tcg_gen_sari_i64(TCGv_i64 ret, TCGv_i64 arg1, int64_t arg2)
 static inline void tcg_gen_brcond_i64(TCGCond cond, TCGv_i64 arg1,
                                       TCGv_i64 arg2, int label_index)
 {
-    tcg_gen_op4ii_i64(INDEX_op_brcond_i64, arg1, arg2, cond, label_index);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_br(label_index);
+    } else if (cond != TCG_COND_NEVER) {
+        tcg_gen_op4ii_i64(INDEX_op_brcond_i64, arg1, arg2, cond, label_index);
+    }
 }
 
 static inline void tcg_gen_setcond_i64(TCGCond cond, TCGv_i64 ret,
                                        TCGv_i64 arg1, TCGv_i64 arg2)
 {
-    tcg_gen_op4i_i64(INDEX_op_setcond_i64, ret, arg1, arg2, cond);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_movi_i64(ret, 1);
+    } else if (cond == TCG_COND_NEVER) {
+        tcg_gen_movi_i64(ret, 0);
+    } else {
+        tcg_gen_op4i_i64(INDEX_op_setcond_i64, ret, arg1, arg2, cond);
+    }
 }
 
 static inline void tcg_gen_mul_i64(TCGv_i64 ret, TCGv_i64 arg1, TCGv_i64 arg2)
@@ -1397,9 +1437,13 @@ static inline void tcg_gen_subi_i64(TCGv_i64 ret, TCGv_i64 arg1, int64_t arg2)
 static inline void tcg_gen_brcondi_i64(TCGCond cond, TCGv_i64 arg1,
                                        int64_t arg2, int label_index)
 {
-    TCGv_i64 t0 = tcg_const_i64(arg2);
-    tcg_gen_brcond_i64(cond, arg1, t0, label_index);
-    tcg_temp_free_i64(t0);
+    if (cond == TCG_COND_ALWAYS) {
+        tcg_gen_br(label_index);
+    } else if (cond != TCG_COND_NEVER) {
+        TCGv_i64 t0 = tcg_const_i64(arg2);
+        tcg_gen_brcond_i64(cond, arg1, t0, label_index);
+        tcg_temp_free_i64(t0);
+    }
 }
 
 static inline void tcg_gen_setcondi_i64(TCGCond cond, TCGv_i64 ret,