tcg: Add support for integer absolute value

Remove a function of the same name from target/arm/.
Use a branchless implementation of abs gleaned from gcc.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

3 files changed, 25 insertions, 10 deletions

diff --git a/target/arm/translate.c b/target/arm/translate.c
index 35bd426a3d..b25781554f 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -604,16 +604,6 @@ static void gen_sar(TCGv_i32 dest, TCGv_i32 t0, TCGv_i32 t1)
     tcg_temp_free_i32(tmp1);
 }
 
-static void tcg_gen_abs_i32(TCGv_i32 dest, TCGv_i32 src)
-{
-    TCGv_i32 c0 = tcg_const_i32(0);
-    TCGv_i32 tmp = tcg_temp_new_i32();
-    tcg_gen_neg_i32(tmp, src);
-    tcg_gen_movcond_i32(TCG_COND_GT, dest, src, c0, src, tmp);
-    tcg_temp_free_i32(c0);
-    tcg_temp_free_i32(tmp);
-}
-
 static void shifter_out_im(TCGv_i32 var, int shift)
 {
     if (shift == 0) {
diff --git a/tcg/tcg-op.c b/tcg/tcg-op.c
index a00d1df37e..0ac291f1c4 100644
--- a/tcg/tcg-op.c
+++ b/tcg/tcg-op.c
@@ -1091,6 +1091,16 @@ void tcg_gen_umax_i32(TCGv_i32 ret, TCGv_i32 a, TCGv_i32 b)
     tcg_gen_movcond_i32(TCG_COND_LTU, ret, a, b, b, a);
 }
 
+void tcg_gen_abs_i32(TCGv_i32 ret, TCGv_i32 a)
+{
+    TCGv_i32 t = tcg_temp_new_i32();
+
+    tcg_gen_sari_i32(t, a, 31);
+    tcg_gen_xor_i32(ret, a, t);
+    tcg_gen_sub_i32(ret, ret, t);
+    tcg_temp_free_i32(t);
+}
+
 /* 64-bit ops */
 
 #if TCG_TARGET_REG_BITS == 32
@@ -2548,6 +2558,16 @@ void tcg_gen_umax_i64(TCGv_i64 ret, TCGv_i64 a, TCGv_i64 b)
     tcg_gen_movcond_i64(TCG_COND_LTU, ret, a, b, b, a);
 }
 
+void tcg_gen_abs_i64(TCGv_i64 ret, TCGv_i64 a)
+{
+    TCGv_i64 t = tcg_temp_new_i64();
+
+    tcg_gen_sari_i64(t, a, 63);
+    tcg_gen_xor_i64(ret, a, t);
+    tcg_gen_sub_i64(ret, ret, t);
+    tcg_temp_free_i64(t);
+}
+
 /* Size changing operations.  */
 
 void tcg_gen_extrl_i64_i32(TCGv_i32 ret, TCGv_i64 arg)
diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
index 472b73cb38..660fe205d0 100644
--- a/tcg/tcg-op.h
+++ b/tcg/tcg-op.h
@@ -335,6 +335,7 @@ 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);
 void tcg_gen_umax_i32(TCGv_i32, TCGv_i32 arg1, TCGv_i32 arg2);
+void tcg_gen_abs_i32(TCGv_i32, TCGv_i32);
 
 static inline void tcg_gen_discard_i32(TCGv_i32 arg)
 {
@@ -534,6 +535,7 @@ void tcg_gen_smin_i64(TCGv_i64, TCGv_i64 arg1, TCGv_i64 arg2);
 void tcg_gen_smax_i64(TCGv_i64, TCGv_i64 arg1, TCGv_i64 arg2);
 void tcg_gen_umin_i64(TCGv_i64, TCGv_i64 arg1, TCGv_i64 arg2);
 void tcg_gen_umax_i64(TCGv_i64, TCGv_i64 arg1, TCGv_i64 arg2);
+void tcg_gen_abs_i64(TCGv_i64, TCGv_i64);
 
 #if TCG_TARGET_REG_BITS == 64
 static inline void tcg_gen_discard_i64(TCGv_i64 arg)
@@ -973,6 +975,7 @@ void tcg_gen_nor_vec(unsigned vece, TCGv_vec r, TCGv_vec a, TCGv_vec b);
 void tcg_gen_eqv_vec(unsigned vece, TCGv_vec r, TCGv_vec a, TCGv_vec b);
 void tcg_gen_not_vec(unsigned vece, TCGv_vec r, TCGv_vec a);
 void tcg_gen_neg_vec(unsigned vece, TCGv_vec r, TCGv_vec a);
+void tcg_gen_abs_vec(unsigned vece, TCGv_vec r, TCGv_vec a);
 void tcg_gen_ssadd_vec(unsigned vece, TCGv_vec r, TCGv_vec a, TCGv_vec b);
 void tcg_gen_usadd_vec(unsigned vece, TCGv_vec r, TCGv_vec a, TCGv_vec b);
 void tcg_gen_sssub_vec(unsigned vece, TCGv_vec r, TCGv_vec a, TCGv_vec b);
@@ -1019,6 +1022,7 @@ void tcg_gen_stl_vec(TCGv_vec r, TCGv_ptr base, TCGArg offset, TCGType t);
 #define tcg_gen_addi_tl tcg_gen_addi_i64
 #define tcg_gen_sub_tl tcg_gen_sub_i64
 #define tcg_gen_neg_tl tcg_gen_neg_i64
+#define tcg_gen_abs_tl tcg_gen_abs_i64
 #define tcg_gen_subfi_tl tcg_gen_subfi_i64
 #define tcg_gen_subi_tl tcg_gen_subi_i64
 #define tcg_gen_and_tl tcg_gen_and_i64
@@ -1131,6 +1135,7 @@ void tcg_gen_stl_vec(TCGv_vec r, TCGv_ptr base, TCGArg offset, TCGType t);
 #define tcg_gen_addi_tl tcg_gen_addi_i32
 #define tcg_gen_sub_tl tcg_gen_sub_i32
 #define tcg_gen_neg_tl tcg_gen_neg_i32
+#define tcg_gen_abs_tl tcg_gen_abs_i32
 #define tcg_gen_subfi_tl tcg_gen_subfi_i32
 #define tcg_gen_subi_tl tcg_gen_subi_i32
 #define tcg_gen_and_tl tcg_gen_and_i32