GlobalISel: constrain G_INSERT to inserting just one value per instruction.

It's much easier to reason about single-value inserts and no-one was actually
using the variadic variants before.

llvm-svn: 296923

2 files changed, 11 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
index 41985e3a328..5eea7268c5e 100644
--- a/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/MachineIRBuilder.cpp
@@ -456,6 +456,15 @@ MachineInstrBuilder MachineIRBuilder::buildUnmerge(ArrayRef<unsigned> Res,
   return MIB;
 }
 
+MachineInstrBuilder MachineIRBuilder::buildInsert(unsigned Res, unsigned Src,
+                                                  unsigned Op, unsigned Index) {
+  return buildInstr(TargetOpcode::G_INSERT)
+      .addDef(Res)
+      .addUse(Src)
+      .addUse(Op)
+      .addImm(Index);
+}
+
 MachineInstrBuilder MachineIRBuilder::buildIntrinsic(Intrinsic::ID ID,
                                                      unsigned Res,
                                                      bool HasSideEffects) {
diff --git a/llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp b/llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp
index 651925e616f..6e6daf81229 100644
--- a/llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp
@@ -88,14 +88,13 @@ AArch64LegalizerInfo::AArch64LegalizerInfo() {
     setAction({BinOp, s64}, Libcall);
   }
 
-  // FIXME: what should we do about G_INSERTs with more than one source value?
-  // For now the default of not specifying means we'll fall back.
-  for (auto Ty : {s32, s64}) {
+  for (auto Ty : {s32, s64, p0}) {
     setAction({G_INSERT, Ty}, Legal);
     setAction({G_INSERT, 1, Ty}, Legal);
   }
   for (auto Ty : {s1, s8, s16}) {
     setAction({G_INSERT, Ty}, WidenScalar);
+    setAction({G_INSERT, 1, Ty}, Legal);
     // FIXME: Can't widen the sources because that violates the constraints on
     // G_INSERT (It seems entirely reasonable that inputs shouldn't overlap).
   }