Inline some java.lang.Math functions.

For a first pass, I inlined the various flavors of abs(), min()/max() on
integers, sqrt(), cos(), and sin().  These were selected based on a
static analysis of a few of our jar files.

A test of repeated sin/cos/sqrt calls on a G1-class device showed an
improvement of 28%.  This would improve more on devices with VFP
support if the VM is compiled with -mfpu=vfp.

Also: clarified a warning and removed some "#if 0" stuff.

3 files changed, 69 insertions, 0 deletions

diff --git a/tests/003-omnibus-opcodes/expected.txt b/tests/003-omnibus-opcodes/expected.txt
index 25ed38ba8..4895dc3e0 100644
--- a/tests/003-omnibus-opcodes/expected.txt
+++ b/tests/003-omnibus-opcodes/expected.txt
@@ -23,6 +23,7 @@ IntMath.truncateTest
 IntMath.divideByZero
 IntMath.bigDivideOverflow
 IntMath.checkConsts
+IntMath.jlmTests
 FloatMath.convTest
 FloatMath.floatOperTest
 FloatMath.doubleOperTest
@@ -39,6 +40,7 @@ FloatMath.checkConvD
  2: 123.45600128173828
 -2.005440939E9, -8.6133032459203287E18, 123.4560012817382
 FloatMath.checkConsts
+FloatMath.jlmTests
 IntMath.testIntCompare
 IntMath.testLongCompare
 IntMath.testFloatCompare
diff --git a/tests/003-omnibus-opcodes/src/FloatMath.java b/tests/003-omnibus-opcodes/src/FloatMath.java
index 0c1fe1ba7..cf4869c26 100644
--- a/tests/003-omnibus-opcodes/src/FloatMath.java
+++ b/tests/003-omnibus-opcodes/src/FloatMath.java
@@ -262,6 +262,50 @@ public class FloatMath {
         assert(d > 9.9 && d < 10.1);
     }
 
+    /*
+     * Determine if two floating point numbers are approximately equal.
+     *
+     * (Assumes that floating point is generally working, so we can't use
+     * this for the first set of tests.)
+     */
+    static boolean approxEqual(float a, float b, float maxDelta) {
+        if (a > b)
+            return (a - b) < maxDelta;
+        else
+            return (b - a) < maxDelta;
+    }
+    static boolean approxEqual(double a, double b, double maxDelta) {
+        if (a > b)
+            return (a - b) < maxDelta;
+        else
+            return (b - a) < maxDelta;
+    }
+
+    /*
+     * Test some java.lang.Math functions.
+     *
+     * The method arguments are positive values.
+     */
+    static void jlmTests(float ff, double dd) {
+        System.out.println("FloatMath.jlmTests");
+
+        assert(approxEqual(Math.abs(ff), ff, 0.001f));
+        assert(approxEqual(Math.abs(-ff), ff, 0.001f));
+        assert(approxEqual(Math.min(ff, -5.0f), -5.0f, 0.001f));
+        assert(approxEqual(Math.max(ff, -5.0f), ff, 0.001f));
+
+        assert(approxEqual(Math.abs(dd), dd, 0.001));
+        assert(approxEqual(Math.abs(-dd), dd, 0.001));
+        assert(approxEqual(Math.min(dd, -5.0), -5.0, 0.001));
+        assert(approxEqual(Math.max(dd, -5.0), dd, 0.001));
+
+        double sq = Math.sqrt(dd);
+        assert(approxEqual(sq*sq, dd, 0.001));
+
+        assert(approxEqual(0.5403023058681398, Math.cos(1.0), 0.00000001));
+        assert(approxEqual(0.8414709848078965, Math.sin(1.0), 0.00000001));
+    }
+
     public static void run() {
         convTest();
 
@@ -287,6 +331,8 @@ public class FloatMath {
         unopTest(123.456f);
 
         checkConsts();
+
+        jlmTests(3.14159f, 123456.78987654321);
     }
 }
 
diff --git a/tests/003-omnibus-opcodes/src/IntMath.java b/tests/003-omnibus-opcodes/src/IntMath.java
index 126bec6cd..d5ac744b8 100644
--- a/tests/003-omnibus-opcodes/src/IntMath.java
+++ b/tests/003-omnibus-opcodes/src/IntMath.java
@@ -432,6 +432,25 @@ public class IntMath {
         assert(huge == 0x9922334455667788L);    // const-wide
     }
 
+    /*
+     * Test some java.lang.Math functions.
+     *
+     * The method arguments are positive values.
+     */
+    static void jlmTests(int ii, long ll) {
+        System.out.println("IntMath.jlmTests");
+
+        assert(Math.abs(ii) == ii);
+        assert(Math.abs(-ii) == ii);
+        assert(Math.min(ii, -5) == -5);
+        assert(Math.max(ii, -5) == ii);
+
+        assert(Math.abs(ll) == ll);
+        assert(Math.abs(-ll) == ll);
+        assert(Math.min(ll, -5L) == -5L);
+        assert(Math.max(ll, -5L) == ll);
+    }
+
     public static void run() {
         shiftTest1();
         shiftTest2();
@@ -467,6 +486,8 @@ public class IntMath {
         checkConsts((byte) 1, (short) -256, -88888, 0x9922334455667788L);
 
         unopCheck(unopTest(38));
+
+        jlmTests(12345, 0x1122334455667788L);
     }
 }