[mips][FastISel] Specify which types we handle for integer extension.

Summary:
Perform integer extension only when the destination type is one of
i8, i16 & i32 and when the source type is i1, i8 or i16. For other
combinations we fall back to SelectionDAG.

This fixes the test MultiSource/Benchmarks/7zip that was failing in our
out-of-tree MIPS buildbots.

Reviewers: dsanders

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9243

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235718 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MipsFastISel.cpp b/lib/Target/Mips/MipsFastISel.cpp
index 605f78d04c3063ad07a0d16951fbc3302e8008bf..265f6de06cb50304e6bfb0b362ef8f3f19e2f0d2 100644 (file)
--- a/lib/Target/Mips/MipsFastISel.cpp
+++ b/lib/Target/Mips/MipsFastISel.cpp
@@ -1394,6 +1394,13 @@ bool MipsFastISel::emitIntZExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
 
 bool MipsFastISel::emitIntExt(MVT SrcVT, unsigned SrcReg, MVT DestVT,
                               unsigned DestReg, bool IsZExt) {
+  // FastISel does not have plumbing to deal with extensions where the SrcVT or
+  // DestVT are odd things, so test to make sure that they are both types we can
+  // handle (i1/i8/i16/i32 for SrcVT and i8/i16/i32/i64 for DestVT), otherwise
+  // bail out to SelectionDAG.
+  if (((DestVT != MVT::i8) && (DestVT != MVT::i16) && (DestVT != MVT::i32)) ||
+      ((SrcVT != MVT::i1) && (SrcVT != MVT::i8) && (SrcVT != MVT::i16)))
+    return false;
   if (IsZExt)
     return emitIntZExt(SrcVT, SrcReg, DestVT, DestReg);
   return emitIntSExt(SrcVT, SrcReg, DestVT, DestReg);