[AArch64][FastISel] Don't even try to select vector icmps.

We used to try to constant-fold them to i32 immediates.
Given that fast-isel doesn't otherwise support vNi1, when selecting
the result users, we'd fallback to SDAG anyway.
However, if the users were in another block, we'd insert broken
cross-class copies (GPR32 to FPR64).

Give up, let SDAG agree with itself on a vNi1 legalization strategy.

llvm-svn: 252364

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64FastISel.cpp b/llvm/lib/Target/AArch64/AArch64FastISel.cpp
index 2f50480efbe..284f5263f90 100644
--- a/llvm/lib/Target/AArch64/AArch64FastISel.cpp
+++ b/llvm/lib/Target/AArch64/AArch64FastISel.cpp
@@ -2451,6 +2451,10 @@ bool AArch64FastISel::selectIndirectBr(const Instruction *I) {
 bool AArch64FastISel::selectCmp(const Instruction *I) {
   const CmpInst *CI = cast<CmpInst>(I);
 
+  // Vectors of i1 are weird: bail out.
+  if (CI->getType()->isVectorTy())
+    return false;
+
   // Try to optimize or fold the cmp.
   CmpInst::Predicate Predicate = optimizeCmpPredicate(CI);
   unsigned ResultReg = 0;