From cf300b91b91d505a4b970d74cae6d06e833b98d7 Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Tue, 24 Aug 2010 10:08:20 -0600
Subject: [PATCH] JIT-inline `even?' and `odd?' on fixnums

---
 collects/tests/racket/optimize.rktl |  8 ++++++++
 src/racket/src/jit.c                | 15 ++++++++++++++-
 src/racket/src/number.c             | 18 ++++++++----------
 3 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/collects/tests/racket/optimize.rktl b/collects/tests/racket/optimize.rktl
index 2949efa7e8..80d01e9b6b 100644
--- a/collects/tests/racket/optimize.rktl
+++ b/collects/tests/racket/optimize.rktl
@@ -173,6 +173,14 @@
     (un #f 'negative? 1)
     (un #t 'negative? -1)
 
+    (un #t 'even? 10)
+    (un #f 'even? 11)
+    (un #t 'even? -10)
+
+    (un #f 'odd? 10)
+    (un #t 'odd? 11)
+    (un #f 'odd? -10)
+
     (un #t 'real? 1)
     (un #t 'real? (expt 2 100))
     (un #t 'real? 1.0)
diff --git a/src/racket/src/jit.c b/src/racket/src/jit.c
index bed4cac536..b99ba0e380 100644
--- a/src/racket/src/jit.c
+++ b/src/racket/src/jit.c
@@ -4418,7 +4418,7 @@ static int can_fast_double(int arith, int cmp, int two_args)
     return 1;
 #endif
 #ifdef INLINE_FP_COMP
-  if (!arith
+  if ((!arith && (cmp != 4) && (cmp != -4))
       || ((arith == 9) /* min */ && two_args)
       || ((arith == 10) /* max */ && two_args))
     return 1;
@@ -4920,6 +4920,7 @@ static int generate_arith(mz_jit_state *jitter, Scheme_Object *rator, Scheme_Obj
         cmp = +/-1 -> >=/<=
         cmp = +/-2 -> >/< or positive/negative?
         cmp = 3 -> bitwise-bit-test?
+        cmp = +/-4 -> even?/odd?
    If rand is NULL, then we're generating part of the fast path for an
    nary arithmatic over a binary operator; the first argument is
    already in R0 (fixnum or min/max) or a floating-point register
@@ -5752,6 +5753,9 @@ static int generate_arith(mz_jit_state *jitter, Scheme_Object *rator, Scheme_Obj
         }
 
         switch (cmp) {
+        case -4:
+          ref3 = jit_bmci_l(jit_forward(), JIT_R0, 0x2);
+          break;
         case -3:
           if (rand2) {
             if (!unsafe_fx || overflow_refslow) {
@@ -5820,6 +5824,9 @@ static int generate_arith(mz_jit_state *jitter, Scheme_Object *rator, Scheme_Obj
             ref3 = jit_bmci_l(jit_forward(), JIT_R0, 1 << (v+1));
           }
           break;
+        case 4:
+          ref3 = jit_bmsi_l(jit_forward(), JIT_R0, 0x2);
+          break;
         }
       }
     } else {
@@ -6452,6 +6459,12 @@ static int generate_inlined_unary(mz_jit_state *jitter, Scheme_App2_Rec *app, in
   } else if (IS_NAMED_PRIM(rator, "positive?")) {
     generate_arith(jitter, rator, app->rand, NULL, 1, 0, 2, 0, for_branch, branch_short, 0, 0, NULL);
     return 1;
+  } else if (IS_NAMED_PRIM(rator, "even?")) {
+    generate_arith(jitter, rator, app->rand, NULL, 1, 0, 4, 0, for_branch, branch_short, 0, 0, NULL);
+    return 1;
+  } else if (IS_NAMED_PRIM(rator, "odd?")) {
+    generate_arith(jitter, rator, app->rand, NULL, 1, 0, -4, 0, for_branch, branch_short, 0, 0, NULL);
+    return 1;
   } else if (IS_NAMED_PRIM(rator, "exact-nonnegative-integer?")
              || IS_NAMED_PRIM(rator, "exact-positive-integer?")) {
     GC_CAN_IGNORE jit_insn *ref, *ref2, *ref3, *ref4;
diff --git a/src/racket/src/number.c b/src/racket/src/number.c
index 1227b205a7..a1196bde8d 100644
--- a/src/racket/src/number.c
+++ b/src/racket/src/number.c
@@ -338,16 +338,14 @@ scheme_init_number (Scheme_Env *env)
 						      "inexact?",
 						      1, 1, 1),
 			     env);
-  scheme_add_global_constant("odd?", 
-			     scheme_make_folding_prim(scheme_odd_p,
-						      "odd?",
-						      1, 1, 1),
-			     env);
-  scheme_add_global_constant("even?", 
-			     scheme_make_folding_prim(even_p,
-						      "even?",
-						      1, 1, 1),
-			     env);
+
+  p = scheme_make_folding_prim(scheme_odd_p, "odd?", 1, 1, 1);
+  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_UNARY_INLINED;
+  scheme_add_global_constant("odd?", p, env);
+  
+  p = scheme_make_folding_prim(even_p, "even?", 1, 1, 1);
+  SCHEME_PRIM_PROC_FLAGS(p) |= SCHEME_PRIM_IS_UNARY_INLINED;
+  scheme_add_global_constant("even?", p, env);
 
   p = scheme_make_folding_prim(scheme_bitwise_and, "bitwise-and", 0, -1, 1);
   SCHEME_PRIM_PROC_FLAGS(p) |= (SCHEME_PRIM_IS_BINARY_INLINED