[PATCH 7/9] mips: Optimize jit_lei / jit_lei_u

[Paul Cercueil]

When working with integers, expressing (reg <= i0) is equivalent to
(reg < i0 + 1).

If (i0 + 1) can fit in a 16-bit signed word, it is then possible to
implement jit_lei() with just one SLTI opcode and jit_lei_u() with just
one SLTIU opcode, respectively.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 lib/jit_mips-cpu.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/lib/jit_mips-cpu.c b/lib/jit_mips-cpu.c
index 35fb9f6..27ef5f7 100644
--- a/lib/jit_mips-cpu.c
+++ b/lib/jit_mips-cpu.c
@@ -1897,10 +1897,8 @@ _lei(jit_state_t *_jit, jit_int32_t r0, jit_int32_t r1, 
jit_word_t i0)
 {
     jit_int32_t                reg;
 
-    if (i0 == 0) {
-       SLT(r0, _ZERO_REGNO, r1);
-       XORI(r0, r0, 1);
-    }
+    if (can_sign_extend_short_p(i0 + 1))
+        SLTI(r0, r1, i0 + 1);
     else {
        reg = jit_get_reg(jit_class_gpr);
        movi(rn(reg), i0);
@@ -1921,10 +1919,8 @@ _lei_u(jit_state_t *_jit, jit_int32_t r0, jit_int32_t 
r1, jit_word_t i0)
 {
     jit_int32_t                reg;
 
-    if (i0 == 0) {
-       SLTU(r0, _ZERO_REGNO, r1);
-       XORI(r0, r0, 1);
-    }
+    if (can_sign_extend_short_p(i0 + 1))
+        SLTIU(r0, r1, i0 + 1);
     else {
        reg = jit_get_reg(jit_class_gpr);
        movi(rn(reg), i0);
-- 
2.35.1