On 21/1/21 21:06, Richard Henderson wrote:
On 1/12/21 11:55 AM, Philippe Mathieu-Daudé wrote:
Convert the following opcodes to decodetree:
- MULT.G - multiply 32-bit signed integers
- MULTU.G - multiply 32-bit unsigned integers
- DMULT.G - multiply 64-bit signed integers
- DMULTU.G - multiply 64-bit unsigned integers
Now that all opcodes from the extension have been converted, we
can remove completely gen_loongson_integer() and its 2 calls in
decode_opc_special2_legacy() and decode_opc_special3_legacy().
Signed-off-by: Philippe Mathieu-Daudé <f4...@amsat.org>
---
target/mips/godson2.decode | 5 ++
target/mips/loong-ext.decode | 5 ++
target/mips/loong_translate.c | 58 ++++++++++++++++++++++
target/mips/translate.c | 92 +----------------------------------
4 files changed, 70 insertions(+), 90 deletions(-)
diff --git a/target/mips/godson2.decode b/target/mips/godson2.decode
index 805452fa975..cf12d9072ec 100644
--- a/target/mips/godson2.decode
+++ b/target/mips/godson2.decode
@@ -13,6 +13,11 @@
@rs_rt_rd ...... rs:5 rt:5 rd:5 ..... ...... &muldiv
+MULT.G 011111 ..... ..... ..... 00000 011000 @rs_rt_rd
+MULTU.G 011111 ..... ..... ..... 00000 011001 @rs_rt_rd
+DMULT.G 011111 ..... ..... ..... 00000 011100 @rs_rt_rd
+DMULTU.G 011111 ..... ..... ..... 00000 011101 @rs_rt_rd
+
DIV.G 011111 ..... ..... ..... 00000 011010 @rs_rt_rd
DIVU.G 011111 ..... ..... ..... 00000 011011 @rs_rt_rd
DDIV.G 011111 ..... ..... ..... 00000 011110 @rs_rt_rd
diff --git a/target/mips/loong-ext.decode b/target/mips/loong-ext.decode
index b0715894ee1..2281afaad95 100644
--- a/target/mips/loong-ext.decode
+++ b/target/mips/loong-ext.decode
@@ -14,6 +14,11 @@
@rs_rt_rd ...... rs:5 rt:5 rd:5 ..... ...... &muldiv
+MULT.G 011100 ..... ..... ..... 00000 010000 @rs_rt_rd
+DMULT.G 011100 ..... ..... ..... 00000 010001 @rs_rt_rd
+MULTU.G 011100 ..... ..... ..... 00000 010010 @rs_rt_rd
+DMULTU.G 011100 ..... ..... ..... 00000 010011 @rs_rt_rd
+
DIV.G 011100 ..... ..... ..... 00000 010100 @rs_rt_rd
DDIV.G 011100 ..... ..... ..... 00000 010101 @rs_rt_rd
DIVU.G 011100 ..... ..... ..... 00000 010110 @rs_rt_rd
diff --git a/target/mips/loong_translate.c b/target/mips/loong_translate.c
index 50609ce4178..2af94535921 100644
--- a/target/mips/loong_translate.c
+++ b/target/mips/loong_translate.c
@@ -263,6 +263,64 @@ static bool trans_DMODU_G(DisasContext *s, arg_muldiv *a)
return gen_lext_MODU_G(s, a->rt, a->rs, a->rd, true);
}
+static bool gen_lext_MULT_G(DisasContext *s, int rd, int rs, int rt,
+ bool is_double, bool is_unsigned)
+{
+ TCGv t0, t1;
+
+ if (is_double) {
+ if (TARGET_LONG_BITS != 64) {
+ return false;
+ }
+ check_mips_64(s);
+ }
+
+ if (rd == 0) {
+ /* Treat as NOP. */
+ return true;
+ }
+
+ t0 = tcg_temp_new();
+ t1 = tcg_temp_new();
+
+ gen_load_gpr(t0, rs);
+ gen_load_gpr(t1, rt);
+
+ if (is_unsigned && !is_double) {
+ tcg_gen_ext32u_tl(t0, t0);
+ tcg_gen_ext32u_tl(t1, t1);
+ }
While this is a faithful conversion of the existing code, these extensions make
no difference to the result. They are redundant with
+ tcg_gen_mul_tl(cpu_gpr[rd], t0, t1);
+ if (!is_double) {
+ tcg_gen_ext32s_tl(cpu_gpr[rd], cpu_gpr[rd]);
this one, which discards any bit that might have been set by the input bits
that are cleared.
I see.
There is no actual difference between MULT.G and MULTU.G, or DMULT.G and
DMULTU.G, because they don't record the most significant bits of the infinite
result in any way.
Right.
+static bool trans_MULT_G(DisasContext *s, arg_muldiv *a)
+{
+ return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, false, false);
+}
+
+static bool trans_MULTU_G(DisasContext *s, arg_muldiv *a)
+{
+ return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, false, true);
+}
+
+static bool trans_DMULT_G(DisasContext *s, arg_muldiv *a)
+{
+ return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, true, false);
+}
+
+static bool trans_DMULTU_G(DisasContext *s, arg_muldiv *a)
+{
+ return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, true, true);
+}
So... if you want to clean this up afterward, or before is up to you.
IIUC you are suggesting this simplification:
-- >8 --
diff --git a/target/mips/tcg/godson2.decode b/target/mips/tcg/godson2.decode
index 4fb8fdba9c..86015ac8e5 100644
--- a/target/mips/tcg/godson2.decode
+++ b/target/mips/tcg/godson2.decode
@@ -15,6 +15,4 @@
-MULT_G 011111 ..... ..... ..... 00000 011000 @rs_rt_rd
-MULTU_G 011111 ..... ..... ..... 00000 011001 @rs_rt_rd
-DMULT_G 011111 ..... ..... ..... 00000 011100 @rs_rt_rd
-DMULTU_G 011111 ..... ..... ..... 00000 011101 @rs_rt_rd
+MULTu_G 011111 ..... ..... ..... 00000 01100- @rs_rt_rd
+DMULTu_G 011111 ..... ..... ..... 00000 01110- @rs_rt_rd
diff --git a/target/mips/tcg/loong-ext.decode
b/target/mips/tcg/loong-ext.decode
index d2c46d3110..b05236eb41 100644
--- a/target/mips/tcg/loong-ext.decode
+++ b/target/mips/tcg/loong-ext.decode
@@ -16,6 +16,4 @@
-MULT_G 011100 ..... ..... ..... 00000 010000 @rs_rt_rd
-DMULT_G 011100 ..... ..... ..... 00000 010001 @rs_rt_rd
-MULTU_G 011100 ..... ..... ..... 00000 010010 @rs_rt_rd
-DMULTU_G 011100 ..... ..... ..... 00000 010011 @rs_rt_rd
+MULTu_G 011100 ..... ..... ..... 00000 0100-0 @rs_rt_rd
+DMULTu_G 011100 ..... ..... ..... 00000 0100-1 @rs_rt_rd
diff --git a/target/mips/tcg/loong_translate.c
b/target/mips/tcg/loong_translate.c
index 672d8b6163..4b6bdf28be 100644
--- a/target/mips/tcg/loong_translate.c
+++ b/target/mips/tcg/loong_translate.c
@@ -253,3 +253,3 @@ static bool trans_DMODU_G(DisasContext *s,
arg_muldiv *a)
static bool gen_lext_MULT_G(DisasContext *s, int rd, int rs, int rt,
- bool is_double, bool is_unsigned)
+ bool is_double)
{
@@ -275,6 +275,2 @@ static bool gen_lext_MULT_G(DisasContext *s, int rd,
int rs, int rt,
- if (is_unsigned && !is_double) {
- tcg_gen_ext32u_tl(t0, t0);
- tcg_gen_ext32u_tl(t1, t1);
- }
tcg_gen_mul_tl(cpu_gpr[rd], t0, t1);
@@ -287,20 +283,10 @@ static bool gen_lext_MULT_G(DisasContext *s, int
rd, int rs, int rt,
-static bool trans_MULT_G(DisasContext *s, arg_muldiv *a)
+static bool trans_MULTu_G(DisasContext *s, arg_muldiv *a)
{
- return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, false, false);
+ return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, false);
}
-static bool trans_MULTU_G(DisasContext *s, arg_muldiv *a)
+static bool trans_DMULTu_G(DisasContext *s, arg_muldiv *a)
{
- return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, false, true);
-}
-
-static bool trans_DMULT_G(DisasContext *s, arg_muldiv *a)
-{
- return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, true, false);
-}
-
-static bool trans_DMULTU_G(DisasContext *s, arg_muldiv *a)
-{
- return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, true, true);
+ return gen_lext_MULT_G(s, a->rt, a->rs, a->rd, true);
}
---
Is that correct?
