Support: Extract ScaledNumbers::getSum() and getDifference()

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211553 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 150 insertions, 0 deletions

diff --git a/unittests/Support/ScaledNumberTest.cpp b/unittests/Support/ScaledNumberTest.cpp
index 08d6c68b0e..48527e5d1b 100644
--- a/unittests/Support/ScaledNumberTest.cpp
+++ b/unittests/Support/ScaledNumberTest.cpp
@@ -386,4 +386,154 @@ TEST(ScaledNumberHelpersTest, matchScales) {
   MATCH_SCALES(uint64_t, 9, 0, UINT64_C(1) << 59, 4, 9, UINT64_C(1) << 63, 0);
 }
 
+TEST(ScaledNumberHelpersTest, getSum) {
+  // Zero.
+  EXPECT_EQ(SP32(1, 0), getSum32(0, 0, 1, 0));
+  EXPECT_EQ(SP32(8, -3), getSum32(0, 0, 8, -3));
+  EXPECT_EQ(SP32(UINT32_MAX, 0), getSum32(0, 0, UINT32_MAX, 0));
+
+  // Basic.
+  EXPECT_EQ(SP32(2, 0), getSum32(1, 0, 1, 0));
+  EXPECT_EQ(SP32(3, 0), getSum32(1, 0, 2, 0));
+  EXPECT_EQ(SP32(67, 0), getSum32(7, 0, 60, 0));
+
+  // Different scales.
+  EXPECT_EQ(SP32(3, 0), getSum32(1, 0, 1, 1));
+  EXPECT_EQ(SP32(4, 0), getSum32(2, 0, 1, 1));
+
+  // Loss of precision.
+  EXPECT_EQ(SP32(UINT32_C(1) << 31, 1), getSum32(1, 32, 1, 0));
+  EXPECT_EQ(SP32(UINT32_C(1) << 31, -31), getSum32(1, -32, 1, 0));
+
+  // Not quite loss of precision.
+  EXPECT_EQ(SP32((UINT32_C(1) << 31) + 1, 1), getSum32(1, 32, 1, 1));
+  EXPECT_EQ(SP32((UINT32_C(1) << 31) + 1, -32), getSum32(1, -32, 1, -1));
+
+  // Overflow.
+  EXPECT_EQ(SP32(UINT32_C(1) << 31, 1), getSum32(1, 0, UINT32_MAX, 0));
+
+  // Reverse operand order.
+  EXPECT_EQ(SP32(1, 0), getSum32(1, 0, 0, 0));
+  EXPECT_EQ(SP32(8, -3), getSum32(8, -3, 0, 0));
+  EXPECT_EQ(SP32(UINT32_MAX, 0), getSum32(UINT32_MAX, 0, 0, 0));
+  EXPECT_EQ(SP32(3, 0), getSum32(2, 0, 1, 0));
+  EXPECT_EQ(SP32(67, 0), getSum32(60, 0, 7, 0));
+  EXPECT_EQ(SP32(3, 0), getSum32(1, 1, 1, 0));
+  EXPECT_EQ(SP32(4, 0), getSum32(1, 1, 2, 0));
+  EXPECT_EQ(SP32(UINT32_C(1) << 31, 1), getSum32(1, 0, 1, 32));
+  EXPECT_EQ(SP32(UINT32_C(1) << 31, -31), getSum32(1, 0, 1, -32));
+  EXPECT_EQ(SP32((UINT32_C(1) << 31) + 1, 1), getSum32(1, 1, 1, 32));
+  EXPECT_EQ(SP32((UINT32_C(1) << 31) + 1, -32), getSum32(1, -1, 1, -32));
+  EXPECT_EQ(SP32(UINT32_C(1) << 31, 1), getSum32(UINT32_MAX, 0, 1, 0));
+
+  // Zero.
+  EXPECT_EQ(SP64(1, 0), getSum64(0, 0, 1, 0));
+  EXPECT_EQ(SP64(8, -3), getSum64(0, 0, 8, -3));
+  EXPECT_EQ(SP64(UINT64_MAX, 0), getSum64(0, 0, UINT64_MAX, 0));
+
+  // Basic.
+  EXPECT_EQ(SP64(2, 0), getSum64(1, 0, 1, 0));
+  EXPECT_EQ(SP64(3, 0), getSum64(1, 0, 2, 0));
+  EXPECT_EQ(SP64(67, 0), getSum64(7, 0, 60, 0));
+
+  // Different scales.
+  EXPECT_EQ(SP64(3, 0), getSum64(1, 0, 1, 1));
+  EXPECT_EQ(SP64(4, 0), getSum64(2, 0, 1, 1));
+
+  // Loss of precision.
+  EXPECT_EQ(SP64(UINT64_C(1) << 63, 1), getSum64(1, 64, 1, 0));
+  EXPECT_EQ(SP64(UINT64_C(1) << 63, -63), getSum64(1, -64, 1, 0));
+
+  // Not quite loss of precision.
+  EXPECT_EQ(SP64((UINT64_C(1) << 63) + 1, 1), getSum64(1, 64, 1, 1));
+  EXPECT_EQ(SP64((UINT64_C(1) << 63) + 1, -64), getSum64(1, -64, 1, -1));
+
+  // Overflow.
+  EXPECT_EQ(SP64(UINT64_C(1) << 63, 1), getSum64(1, 0, UINT64_MAX, 0));
+
+  // Reverse operand order.
+  EXPECT_EQ(SP64(1, 0), getSum64(1, 0, 0, 0));
+  EXPECT_EQ(SP64(8, -3), getSum64(8, -3, 0, 0));
+  EXPECT_EQ(SP64(UINT64_MAX, 0), getSum64(UINT64_MAX, 0, 0, 0));
+  EXPECT_EQ(SP64(3, 0), getSum64(2, 0, 1, 0));
+  EXPECT_EQ(SP64(67, 0), getSum64(60, 0, 7, 0));
+  EXPECT_EQ(SP64(3, 0), getSum64(1, 1, 1, 0));
+  EXPECT_EQ(SP64(4, 0), getSum64(1, 1, 2, 0));
+  EXPECT_EQ(SP64(UINT64_C(1) << 63, 1), getSum64(1, 0, 1, 64));
+  EXPECT_EQ(SP64(UINT64_C(1) << 63, -63), getSum64(1, 0, 1, -64));
+  EXPECT_EQ(SP64((UINT64_C(1) << 63) + 1, 1), getSum64(1, 1, 1, 64));
+  EXPECT_EQ(SP64((UINT64_C(1) << 63) + 1, -64), getSum64(1, -1, 1, -64));
+  EXPECT_EQ(SP64(UINT64_C(1) << 63, 1), getSum64(UINT64_MAX, 0, 1, 0));
+}
+
+TEST(ScaledNumberHelpersTest, getDifference) {
+  // Basic.
+  EXPECT_EQ(SP32(0, 0), getDifference32(1, 0, 1, 0));
+  EXPECT_EQ(SP32(1, 0), getDifference32(2, 0, 1, 0));
+  EXPECT_EQ(SP32(53, 0), getDifference32(60, 0, 7, 0));
+
+  // Equals "0", different scales.
+  EXPECT_EQ(SP32(0, 0), getDifference32(2, 0, 1, 1));
+
+  // Subtract "0".
+  EXPECT_EQ(SP32(1, 0), getDifference32(1, 0, 0, 0));
+  EXPECT_EQ(SP32(8, -3), getDifference32(8, -3, 0, 0));
+  EXPECT_EQ(SP32(UINT32_MAX, 0), getDifference32(UINT32_MAX, 0, 0, 0));
+
+  // Loss of precision.
+  EXPECT_EQ(SP32((UINT32_C(1) << 31) + 1, 1),
+            getDifference32((UINT32_C(1) << 31) + 1, 1, 1, 0));
+  EXPECT_EQ(SP32((UINT32_C(1) << 31) + 1, -31),
+            getDifference32((UINT32_C(1) << 31) + 1, -31, 1, -32));
+
+  // Not quite loss of precision.
+  EXPECT_EQ(SP32(UINT32_MAX, 0), getDifference32(1, 32, 1, 0));
+  EXPECT_EQ(SP32(UINT32_MAX, -32), getDifference32(1, 0, 1, -32));
+
+  // Saturate to "0".
+  EXPECT_EQ(SP32(0, 0), getDifference32(0, 0, 1, 0));
+  EXPECT_EQ(SP32(0, 0), getDifference32(0, 0, 8, -3));
+  EXPECT_EQ(SP32(0, 0), getDifference32(0, 0, UINT32_MAX, 0));
+  EXPECT_EQ(SP32(0, 0), getDifference32(7, 0, 60, 0));
+  EXPECT_EQ(SP32(0, 0), getDifference32(1, 0, 1, 1));
+  EXPECT_EQ(SP32(0, 0), getDifference32(1, -32, 1, 0));
+  EXPECT_EQ(SP32(0, 0), getDifference32(1, -32, 1, -1));
+
+  // Regression tests for cases that failed during bringup.
+  EXPECT_EQ(SP32(UINT32_C(1) << 26, -31),
+            getDifference32(1, 0, UINT32_C(31) << 27, -32));
+
+  // Basic.
+  EXPECT_EQ(SP64(0, 0), getDifference64(1, 0, 1, 0));
+  EXPECT_EQ(SP64(1, 0), getDifference64(2, 0, 1, 0));
+  EXPECT_EQ(SP64(53, 0), getDifference64(60, 0, 7, 0));
+
+  // Equals "0", different scales.
+  EXPECT_EQ(SP64(0, 0), getDifference64(2, 0, 1, 1));
+
+  // Subtract "0".
+  EXPECT_EQ(SP64(1, 0), getDifference64(1, 0, 0, 0));
+  EXPECT_EQ(SP64(8, -3), getDifference64(8, -3, 0, 0));
+  EXPECT_EQ(SP64(UINT64_MAX, 0), getDifference64(UINT64_MAX, 0, 0, 0));
+
+  // Loss of precision.
+  EXPECT_EQ(SP64((UINT64_C(1) << 63) + 1, 1),
+            getDifference64((UINT64_C(1) << 63) + 1, 1, 1, 0));
+  EXPECT_EQ(SP64((UINT64_C(1) << 63) + 1, -63),
+            getDifference64((UINT64_C(1) << 63) + 1, -63, 1, -64));
+
+  // Not quite loss of precision.
+  EXPECT_EQ(SP64(UINT64_MAX, 0), getDifference64(1, 64, 1, 0));
+  EXPECT_EQ(SP64(UINT64_MAX, -64), getDifference64(1, 0, 1, -64));
+
+  // Saturate to "0".
+  EXPECT_EQ(SP64(0, 0), getDifference64(0, 0, 1, 0));
+  EXPECT_EQ(SP64(0, 0), getDifference64(0, 0, 8, -3));
+  EXPECT_EQ(SP64(0, 0), getDifference64(0, 0, UINT64_MAX, 0));
+  EXPECT_EQ(SP64(0, 0), getDifference64(7, 0, 60, 0));
+  EXPECT_EQ(SP64(0, 0), getDifference64(1, 0, 1, 1));
+  EXPECT_EQ(SP64(0, 0), getDifference64(1, -64, 1, 0));
+  EXPECT_EQ(SP64(0, 0), getDifference64(1, -64, 1, -1));
+}
+
 } // end namespace