[PATCH 01/12] tcg/tcg-op: Factor tcg_gen_hrev32_i32() out

[Philippe Mathieu-Daudé]

Byteswapping each halfword is a common operation, so
extract to a new tcg_gen_hrev32_i32() generic helper.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 docs/devel/tcg-ops.rst      |  4 ++++
 include/tcg/tcg-op-common.h |  1 +
 tcg/tcg-op.c                | 29 +++++++++++++++++++++++------
 3 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/docs/devel/tcg-ops.rst b/docs/devel/tcg-ops.rst
index 7ea6aba502..17965faa03 100644
--- a/docs/devel/tcg-ops.rst
+++ b/docs/devel/tcg-ops.rst
@@ -490,6 +490,10 @@ Misc
          into 32-bit output *t0*.  Depending on the host, this may be a simple 
shift,
          or may require additional canonicalization.
 
+   * - hrev32_i32 *t0*, *t1*
+
+     - | Byteswap each halfword within a 32-bit value.
+
    * - hswap_i32/i64 *t0*, *t1*
 
      - | Swap 16-bit halfwords within a 32/64-bit value.
diff --git a/include/tcg/tcg-op-common.h b/include/tcg/tcg-op-common.h
index be382bbf77..bb515dfd51 100644
--- a/include/tcg/tcg-op-common.h
+++ b/include/tcg/tcg-op-common.h
@@ -360,6 +360,7 @@ void tcg_gen_ext16u_i32(TCGv_i32 ret, TCGv_i32 arg);
 void tcg_gen_bswap16_i32(TCGv_i32 ret, TCGv_i32 arg, int flags);
 void tcg_gen_bswap32_i32(TCGv_i32 ret, TCGv_i32 arg);
 void tcg_gen_hswap_i32(TCGv_i32 ret, TCGv_i32 arg);
+void tcg_gen_hrev32_i32(TCGv_i32 ret, TCGv_i32 arg);
 void tcg_gen_smin_i32(TCGv_i32, TCGv_i32 arg1, TCGv_i32 arg2);
 void tcg_gen_smax_i32(TCGv_i32, TCGv_i32 arg1, TCGv_i32 arg2);
 void tcg_gen_umin_i32(TCGv_i32, TCGv_i32 arg1, TCGv_i32 arg2);
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index c436c5e263..b1b5d9b45b 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -1073,14 +1073,9 @@ void tcg_gen_bswap32_i32(TCGv_i32 ret, TCGv_i32 arg)
     } else {
         TCGv_i32 t0 = tcg_temp_ebb_new_i32();
         TCGv_i32 t1 = tcg_temp_ebb_new_i32();
-        TCGv_i32 t2 = tcg_constant_i32(0x00ff00ff);
 
                                         /* arg = abcd */
-        tcg_gen_shri_i32(t0, arg, 8);   /*  t0 = .abc */
-        tcg_gen_and_i32(t1, arg, t2);   /*  t1 = .b.d */
-        tcg_gen_and_i32(t0, t0, t2);    /*  t0 = .a.c */
-        tcg_gen_shli_i32(t1, t1, 8);    /*  t1 = b.d. */
-        tcg_gen_or_i32(ret, t0, t1);    /* ret = badc */
+        tcg_gen_hrev32_i32(ret, arg);   /* ret = badc */
 
         tcg_gen_shri_i32(t0, ret, 16);  /*  t0 = ..ba */
         tcg_gen_shli_i32(t1, ret, 16);  /*  t1 = dc.. */
@@ -1102,6 +1097,28 @@ void tcg_gen_hswap_i32(TCGv_i32 ret, TCGv_i32 arg)
     tcg_gen_rotli_i32(ret, arg, 16);
 }
 
+/*
+ * hswap_i32: Byteswap each halfword within a 32-bit value.
+ *
+ * Byte pattern:  hswap_i32(abcd) -> badc
+ */
+void tcg_gen_hrev32_i32(TCGv_i32 ret, TCGv_i32 arg)
+{
+    TCGv_i32 mask = tcg_constant_i32(0x00ff00ff);
+    TCGv_i32 t0 = tcg_temp_ebb_new_i32();
+    TCGv_i32 t1 = tcg_temp_ebb_new_i32();
+
+                                        /* arg = abcd */
+    tcg_gen_shri_i32(t0, arg, 8);       /*  t0 = .abc */
+    tcg_gen_and_i32(t1, arg, mask);     /*  t1 = .b.d */
+    tcg_gen_and_i32(t0, t0, mask);      /*  t0 = .a.c */
+    tcg_gen_shli_i32(t1, t1, 8);        /*  t1 = b.d. */
+    tcg_gen_or_i32(ret, t0, t1);        /* ret = badc */
+
+    tcg_temp_free_i32(t0);
+    tcg_temp_free_i32(t1);
+}
+
 void tcg_gen_smin_i32(TCGv_i32 ret, TCGv_i32 a, TCGv_i32 b)
 {
     tcg_gen_movcond_i32(TCG_COND_LT, ret, a, b, a, b);
-- 
2.41.0