From 8a1a2a60336264a5f96fae4c7f02424c6928b7c3 Mon Sep 17 00:00:00 2001
From: Michael Matz <matz@suse.de>
Date: Wed, 13 Jul 2016 15:11:40 +0200
Subject: [PATCH] Implement __builtin_choose_expr

Follows GCC implementation.
---
 tccgen.c        | 29 +++++++++++++++++++++++++++++
 tcctok.h        |  1 +
 tests/tcctest.c | 13 +++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/tccgen.c b/tccgen.c
index bbe1d83..c006f71 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -4238,6 +4238,35 @@ ST_FUNC void unary(void)
             vpushi(is_compatible_types(&type1, &type2));
         }
         break;
+    case TOK_builtin_choose_expr:
+	{
+	    int saved_nocode_wanted, c;
+	    next();
+	    skip('(');
+	    c = expr_const();
+	    skip(',');
+	    if (!c) {
+		saved_nocode_wanted = nocode_wanted;
+		nocode_wanted = 1;
+	    }
+	    expr_eq();
+	    if (!c) {
+		vpop();
+		nocode_wanted = saved_nocode_wanted;
+	    }
+	    skip(',');
+	    if (c) {
+		saved_nocode_wanted = nocode_wanted;
+		nocode_wanted = 1;
+	    }
+	    expr_eq();
+	    if (c) {
+		vpop();
+		nocode_wanted = saved_nocode_wanted;
+	    }
+	    skip(')');
+	}
+        break;
     case TOK_builtin_constant_p:
         {
             int saved_nocode_wanted, res;
diff --git a/tcctok.h b/tcctok.h
index ec69908..9bbe879 100644
--- a/tcctok.h
+++ b/tcctok.h
@@ -132,6 +132,7 @@
      DEF(TOK_VISIBILITY1, "visibility")
      DEF(TOK_VISIBILITY2, "__visibility__")
      DEF(TOK_builtin_types_compatible_p, "__builtin_types_compatible_p")
+     DEF(TOK_builtin_choose_expr, "__builtin_choose_expr")
      DEF(TOK_builtin_constant_p, "__builtin_constant_p")
      DEF(TOK_builtin_frame_address, "__builtin_frame_address")
      DEF(TOK_builtin_return_address, "__builtin_return_address")
diff --git a/tests/tcctest.c b/tests/tcctest.c
index 57226f7..10033a4 100644
--- a/tests/tcctest.c
+++ b/tests/tcctest.c
@@ -2685,6 +2685,9 @@ int constant_p_var;
 
 void builtin_test(void)
 {
+    short s;
+    int i;
+    long long ll;
 #if GCC_MAJOR >= 3
     COMPAT_TYPE(int, int);
     COMPAT_TYPE(int, unsigned int);
@@ -2704,6 +2707,16 @@ void builtin_test(void)
     printf("res = %d\n", __builtin_constant_p(1 + 2));
     printf("res = %d\n", __builtin_constant_p(&constant_p_var));
     printf("res = %d\n", __builtin_constant_p(constant_p_var));
+    s = 1;
+    ll = 2;
+    i = __builtin_choose_expr (1 != 0, ll, s);
+    printf("bce: %d\n", i);
+    i = __builtin_choose_expr (1 != 1, ll, s);
+    printf("bce: %d\n", i);
+    i = sizeof (__builtin_choose_expr (1, ll, s));
+    printf("bce: %d\n", i);
+    i = sizeof (__builtin_choose_expr (0, ll, s));
+    printf("bce: %d\n", i);
 }
 
 #ifndef _WIN32