The following patch provides builtin support for byte swapping and bit counting. On suitable hardware, these generate the x86 popcount instructions, as also generated by the SUN HotSpot JIT/JVM for these method calls.
java.lang.Integer.bitCount -> __builtin_popcount
java.lang.Long.bitCount -> __builtin_popcountl
java.lang.Short.reverseBytes -> __builtin_bswap16
java.lang.Integer.reverseBytes -> __builtin_bswap32
java.lang.Long.reverseBytes -> __builtin_bswap64
New test cases have been added to libjava to double check nothing breaks.
Whist I was there I noticed that the math builtins (many of which I added
support for
back in 2003/2004) weren't marked as ECF_LEAF, indicating that they don't/can't
invoke any user specified functions. This has also been fixed in the patch
below.
The following patch has been tested on x86_64-pc-linux-gnu with a full make
bootstrap
and make check with no new failures/regressions.
Ok for stage1 once it reopens?
Cheers,
Roger
--
Roger Sayle, Ph.D.
CEO and founder
NextMove Software Limited
Registered in England No. 07588305
Registered Office: Innovation Centre (Unit 23), Cambridge Science Park,
Cambridge CB4 0EY
2016-02-21 Roger Sayle <ro...@nextmovesoftware.com>
gcc/java:
* builtins.c (java_builtins): Use popcount* and bswap* builtins to
implement bitCount() and reverseBytes() methods in java.lang.Integer
and friends.
(initialize_builtins): Annotate math builtins with ECF_LEAF. Call
define_builtin for the new popcount* and bswap* builtins.
libjava:
* testsuite/libjava.lang/BuiltinBitCount.java: New test case.
* testsuite/libjava.lang/BuiltinReverseBytes.java: Likewise.
Index: builtins.c
===================================================================
--- builtins.c (revision 233190)
+++ builtins.c (working copy)
@@ -98,6 +98,11 @@
{ { "java.lang.Math" }, { "sin" }, NULL, BUILT_IN_SIN },
{ { "java.lang.Math" }, { "sqrt" }, NULL, BUILT_IN_SQRT },
{ { "java.lang.Math" }, { "tan" }, NULL, BUILT_IN_TAN },
+ { { "java.lang.Integer" }, { "bitCount" }, NULL, BUILT_IN_POPCOUNT },
+ { { "java.lang.Integer" }, { "reverseBytes" }, NULL, BUILT_IN_BSWAP32 },
+ { { "java.lang.Long" }, { "bitCount" }, NULL, BUILT_IN_POPCOUNTL },
+ { { "java.lang.Long" }, { "reverseBytes" }, NULL, BUILT_IN_BSWAP64 },
+ { { "java.lang.Short" }, { "reverseBytes" }, NULL, BUILT_IN_BSWAP16 },
{ { "java.lang.Float" }, { "intBitsToFloat" }, convert_real,
(enum built_in_function) 0 },
{ { "java.lang.Double" }, { "longBitsToDouble" }, convert_real,
@@ -483,6 +488,7 @@
tree double_ftype_double, double_ftype_double_double;
tree float_ftype_float_float;
tree boolean_ftype_boolean_boolean;
+ tree int_ftype_int;
int i;
for (i = 0; java_builtins[i].builtin_code != END_BUILTINS; ++i)
@@ -507,50 +513,77 @@
double_type_node, double_type_node, NULL_TREE);
define_builtin (BUILT_IN_FMOD, "__builtin_fmod",
- double_ftype_double_double, "fmod", ECF_CONST);
+ double_ftype_double_double, "fmod", ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_FMODF, "__builtin_fmodf",
- float_ftype_float_float, "fmodf", ECF_CONST);
+ float_ftype_float_float, "fmodf", ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_ACOS, "__builtin_acos",
double_ftype_double, "_ZN4java4lang4Math4acosEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_ASIN, "__builtin_asin",
double_ftype_double, "_ZN4java4lang4Math4asinEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_ATAN, "__builtin_atan",
double_ftype_double, "_ZN4java4lang4Math4atanEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_ATAN2, "__builtin_atan2",
double_ftype_double_double, "_ZN4java4lang4Math5atan2EJddd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_CEIL, "__builtin_ceil",
double_ftype_double, "_ZN4java4lang4Math4ceilEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_COS, "__builtin_cos",
double_ftype_double, "_ZN4java4lang4Math3cosEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_EXP, "__builtin_exp",
double_ftype_double, "_ZN4java4lang4Math3expEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_FLOOR, "__builtin_floor",
double_ftype_double, "_ZN4java4lang4Math5floorEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_LOG, "__builtin_log",
double_ftype_double, "_ZN4java4lang4Math3logEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_POW, "__builtin_pow",
double_ftype_double_double, "_ZN4java4lang4Math3powEJddd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_SIN, "__builtin_sin",
double_ftype_double, "_ZN4java4lang4Math3sinEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_SQRT, "__builtin_sqrt",
double_ftype_double, "_ZN4java4lang4Math4sqrtEJdd",
- ECF_CONST);
+ ECF_CONST | ECF_LEAF);
define_builtin (BUILT_IN_TAN, "__builtin_tan",
double_ftype_double, "_ZN4java4lang4Math3tanEJdd",
- ECF_CONST);
-
+ ECF_CONST | ECF_LEAF);
+
+ int_ftype_int = build_function_type_list (int_type_node,
+ int_type_node, NULL_TREE);
+
+ define_builtin (BUILT_IN_POPCOUNT, "__builtin_popcount", int_ftype_int,
+ "_ZN4java4lang7Integer8bitCountEJii",
+ ECF_CONST | ECF_LEAF | ECF_NOTHROW);
+ define_builtin (BUILT_IN_BSWAP32, "__builtin_bswap32", int_ftype_int,
+ "_ZN4java4lang7Integer12reverseBytesEJii",
+ ECF_CONST | ECF_LEAF | ECF_NOTHROW);
+
+ define_builtin (BUILT_IN_POPCOUNTL, "__builtin_popcountl",
+ build_function_type_list (int_type_node,
+ long_type_node, NULL_TREE),
+ "_ZN4java4lang4Long8bitCountEJix",
+ ECF_CONST | ECF_LEAF | ECF_NOTHROW);
+ define_builtin (BUILT_IN_BSWAP64, "__builtin_bswap64",
+ build_function_type_list (long_type_node,
+ long_type_node, NULL_TREE),
+ "_ZN4java4lang4Long12reverseBytesEJxx",
+ ECF_CONST | ECF_LEAF | ECF_NOTHROW);
+
+ define_builtin (BUILT_IN_BSWAP16, "__builtin_bswap16",
+ build_function_type_list (short_type_node,
+ short_type_node, NULL_TREE),
+ "_ZN4java4lang5Short12reverseBytesEJss",
+ ECF_CONST | ECF_LEAF | ECF_NOTHROW);
+
boolean_ftype_boolean_boolean
= build_function_type_list (boolean_type_node,
boolean_type_node, boolean_type_node,
BuiltinBitCount.java
Description: Binary data
BuiltinReverseBytes.java
Description: Binary data
