From ec96592702ea4c0f16c661d2d710bb486488809c Mon Sep 17 00:00:00 2001
From: Matthew Flatt <mflatt@racket-lang.org>
Date: Tue, 27 May 2014 08:59:03 +0100
Subject: [PATCH] optimizer: treat known procedure bindings, etc., as #t for
 `if`

Closes PR 14526
---
 .../racket-test/tests/racket/optimize.rktl    | 30 +++++++++++++++++++
 racket/src/racket/src/optimize.c              | 23 +++++++++++---
 racket/src/racket/src/schvers.h               |  4 +--
 3 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/pkgs/racket-pkgs/racket-test/tests/racket/optimize.rktl b/pkgs/racket-pkgs/racket-test/tests/racket/optimize.rktl
index 94bcdc7e3c..25befdf4f9 100644
--- a/pkgs/racket-pkgs/racket-test/tests/racket/optimize.rktl
+++ b/pkgs/racket-pkgs/racket-test/tests/racket/optimize.rktl
@@ -1158,6 +1158,36 @@
                              (a1)
                              (a2))))
 
+(test-comp '(lambda (y)
+              (let ([f (lambda (x) x)])
+                (if f
+                    (+ y 1)
+                    (- y 1))))
+           '(lambda (y)
+              (+ y 1)))
+
+(test-comp '(module m racket/base
+              (define (f x) x)
+              (define (g y)
+                (if f
+                    (+ y 1)
+                    (- y 1))))
+           '(module m racket/base
+              (define (f x) x)
+              (define (g y)
+                (+ y 1))))
+
+(test-comp '(module m racket/base
+              (struct p (x y) #:omit-define-syntaxes)
+              (define (g y)
+                (if p-x
+                    (+ y 1)
+                    (- y 1))))
+           '(module m racket/base
+              (struct p (x y) #:omit-define-syntaxes)
+              (define (g y)
+                (+ y 1))))
+
 (test-comp '(values 10)
            10)
 (test-comp '(let ([x (values 10)])
diff --git a/racket/src/racket/src/optimize.c b/racket/src/racket/src/optimize.c
index c67f87a6cb..eca6a55c5c 100644
--- a/racket/src/racket/src/optimize.c
+++ b/racket/src/racket/src/optimize.c
@@ -6005,7 +6005,10 @@ Scheme_Object *scheme_optimize_expr(Scheme_Object *expr, Optimize_Info *info, in
   case scheme_with_cont_mark_type:
     return optimize_wcm(expr, info, context);
   case scheme_compiled_unclosed_procedure_type:
-    return optimize_closure_compilation(expr, info, context);
+    if (context & OPT_CONTEXT_BOOLEAN)
+      return scheme_true;
+    else
+      return optimize_closure_compilation(expr, info, context);
   case scheme_compiled_let_void_type:
     return scheme_optimize_lets(expr, info, 0, context);
   case scheme_compiled_toplevel_type:
@@ -6025,6 +6028,9 @@ Scheme_Object *scheme_optimize_expr(Scheme_Object *expr, Optimize_Info *info, in
       }
 
       if (c) {
+        if (context & OPT_CONTEXT_BOOLEAN)
+          return (SCHEME_FALSEP(c) ? scheme_false : scheme_true);
+
 	if (scheme_compiled_duplicate_ok(c, 0))
 	  return c;
 
@@ -6052,8 +6058,12 @@ Scheme_Object *scheme_optimize_expr(Scheme_Object *expr, Optimize_Info *info, in
     optimize_info_used_top(info);
     return expr;
   case scheme_compiled_quote_syntax_type:
-    info->size += 1;
-    optimize_info_used_top(info);
+    if (context & OPT_CONTEXT_BOOLEAN)
+      return scheme_true;
+    else {
+      info->size += 1;
+      optimize_info_used_top(info);
+    }
     return expr;
   case scheme_variable_type:
   case scheme_module_variable_type:
@@ -6070,7 +6080,10 @@ Scheme_Object *scheme_optimize_expr(Scheme_Object *expr, Optimize_Info *info, in
   case scheme_begin_for_syntax_type:
     return begin_for_syntax_optimize(expr, info, context);
   case scheme_case_lambda_sequence_type:
-    return case_lambda_optimize(expr, info, context);
+    if (context & OPT_CONTEXT_BOOLEAN)
+      return scheme_true;
+    else
+      return case_lambda_optimize(expr, info, context);
   case scheme_begin0_sequence_type:
     return begin0_optimize(expr, info, context);
   case scheme_apply_values_type:
@@ -6943,11 +6956,13 @@ static Scheme_Object *do_optimize_info_lookup(Optimize_Info *info, int pos, int
       if (single_use)
         *single_use = SCHEME_TRUEP(SCHEME_VEC_ELS(p)[3]);
       if (SAME_TYPE(SCHEME_TYPE(n), scheme_compiled_unclosed_procedure_type)) {
+        if (context & OPT_CONTEXT_BOOLEAN) return scheme_true;
 	if (!closure_offset)
 	  break;
 	else
           *closure_offset = delta;
       } else if (SAME_TYPE(SCHEME_TYPE(n), scheme_case_lambda_sequence_type)) {
+        if (context & OPT_CONTEXT_BOOLEAN) return scheme_true;
         if (!closure_offset)
 	  break;
 	else
diff --git a/racket/src/racket/src/schvers.h b/racket/src/racket/src/schvers.h
index a53bd53a61..4c80ac13a0 100644
--- a/racket/src/racket/src/schvers.h
+++ b/racket/src/racket/src/schvers.h
@@ -13,12 +13,12 @@
    consistently.)
 */
 
-#define MZSCHEME_VERSION "6.0.1.10"
+#define MZSCHEME_VERSION "6.0.1.11"
 
 #define MZSCHEME_VERSION_X 6
 #define MZSCHEME_VERSION_Y 0
 #define MZSCHEME_VERSION_Z 1
-#define MZSCHEME_VERSION_W 10
+#define MZSCHEME_VERSION_W 11
 
 #define MZSCHEME_VERSION_MAJOR ((MZSCHEME_VERSION_X * 100) + MZSCHEME_VERSION_Y)
 #define MZSCHEME_VERSION_MINOR ((MZSCHEME_VERSION_Z * 1000) + MZSCHEME_VERSION_W)