commit b2c184458e990c8faeffd5047e7086e4f7ff07a6
author Roman Lebedev <lebedev.ri@gmail.com> Fri Oct 25 18:17:38 2019 +0300
committer Roman Lebedev <lebedev.ri@gmail.com> Fri Oct 25 18:19:54 2019 +0300
tree 1b2be1eeb77db6e5857631ac17d9eec37cbc7d6a
parent 59a51d84b3a4f96bcc9669ee9c2b2041175a2ccd

[APInt] Add saturating multiply ops

Summary:
There are `*_ov()` functions already, so at least for consistency it may be good to also have saturating variants.
These may or may not be needed for `ConstantRange`'s `mulWithNoWrap()`

Reviewers: spatel, nikic

Reviewed By: nikic

Subscribers: hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D69397

llvm/unittests/ADT/APIntTest.cpp

diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index a58d314..f45a4e6 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -1197,6 +1197,24 @@
   EXPECT_EQ(APInt(8, 127), AP_100.ssub_sat(-AP_100));
   EXPECT_EQ(APInt(8, -128), (-AP_100).ssub_sat(AP_100));
   EXPECT_EQ(APInt(8, -128), APInt(8, -128).ssub_sat(APInt(8, 127)));
+
+  EXPECT_EQ(APInt(8, 250), APInt(8, 50).umul_sat(APInt(8, 5)));
+  EXPECT_EQ(APInt(8, 255), APInt(8, 50).umul_sat(APInt(8, 6)));
+  EXPECT_EQ(APInt(8, 255), APInt(8, -128).umul_sat(APInt(8, 3)));
+  EXPECT_EQ(APInt(8, 255), APInt(8, 3).umul_sat(APInt(8, -128)));
+  EXPECT_EQ(APInt(8, 255), APInt(8, -128).umul_sat(APInt(8, -128)));
+
+  EXPECT_EQ(APInt(8, 125), APInt(8, 25).smul_sat(APInt(8, 5)));
+  EXPECT_EQ(APInt(8, 127), APInt(8, 25).smul_sat(APInt(8, 6)));
+  EXPECT_EQ(APInt(8, 127), APInt(8, 127).smul_sat(APInt(8, 127)));
+  EXPECT_EQ(APInt(8, -125), APInt(8, -25).smul_sat(APInt(8, 5)));
+  EXPECT_EQ(APInt(8, -125), APInt(8, 25).smul_sat(APInt(8, -5)));
+  EXPECT_EQ(APInt(8, 125), APInt(8, -25).smul_sat(APInt(8, -5)));
+  EXPECT_EQ(APInt(8, 125), APInt(8, 25).smul_sat(APInt(8, 5)));
+  EXPECT_EQ(APInt(8, -128), APInt(8, -25).smul_sat(APInt(8, 6)));
+  EXPECT_EQ(APInt(8, -128), APInt(8, 25).smul_sat(APInt(8, -6)));
+  EXPECT_EQ(APInt(8, 127), APInt(8, -25).smul_sat(APInt(8, -6)));
+  EXPECT_EQ(APInt(8, 127), APInt(8, 25).smul_sat(APInt(8, 6)));
 }
 
 TEST(APIntTest, FromArray) {