From: Pete Couperus <petecoup@synopsys.com>
Date: Mon, 20 May 2019 18:09:37 +0000 (+0000)
Subject: [TableGen] - Type comparison LE should be LT or equal.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=594d5b198e4b881dae6cc99c997ac3c87fd54fb9;p=llvm

[TableGen] - Type comparison LE should be LT or equal.

Differential Revision: https://reviews.llvm.org/D61705

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361183 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/utils/TableGen/CodeGenDAGPatterns.cpp b/utils/TableGen/CodeGenDAGPatterns.cpp
index 0b1687d3e92..4b491bf3c92 100644
--- a/utils/TableGen/CodeGenDAGPatterns.cpp
+++ b/utils/TableGen/CodeGenDAGPatterns.cpp
@@ -507,22 +507,14 @@ bool TypeInfer::EnforceSmallerThan(TypeSetByHwMode &Small,
            (A.getScalarSizeInBits() == B.getScalarSizeInBits() &&
             A.getSizeInBits() < B.getSizeInBits());
   };
-  auto LE = [](MVT A, MVT B) -> bool {
+  auto LE = [&LT](MVT A, MVT B) -> bool {
     // This function is used when removing elements: when a vector is compared
     // to a non-vector, it should return false (to avoid removal).
     if (A.isVector() != B.isVector())
       return false;
 
-    // Note on the < comparison below:
-    // X86 has patterns like
-    //   (set VR128X:$dst, (v16i8 (X86vtrunc (v4i32 VR128X:$src1)))),
-    // where the truncated vector is given a type v16i8, while the source
-    // vector has type v4i32. They both have the same size in bits.
-    // The minimal type in the result is obviously v16i8, and when we remove
-    // all types from the source that are smaller-or-equal than v8i16, the
-    // only source type would also be removed (since it's equal in size).
-    return A.getScalarSizeInBits() <= B.getScalarSizeInBits() ||
-           A.getSizeInBits() < B.getSizeInBits();
+    return LT(A, B) || (A.getScalarSizeInBits() == B.getScalarSizeInBits() &&
+                        A.getSizeInBits() == B.getSizeInBits());
   };
 
   for (unsigned M : Modes) {