[TargetPassConfig] Add a target hook to know what GlobalISel should do on error.

By default, this hook tells GlobalISel to abort (report a fatal error)
when it encounters an error. The alternative will be to fall back on
SDISel.
This fall back will be removed when the bring-up of GlobalISel is over.

llvm-svn: 279879

1 files changed, 13 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/TargetPassConfig.cpp b/llvm/lib/CodeGen/TargetPassConfig.cpp
index 94ee30264dd..88b94f51928 100644
--- a/llvm/lib/CodeGen/TargetPassConfig.cpp
+++ b/llvm/lib/CodeGen/TargetPassConfig.cpp
@@ -98,6 +98,12 @@ PrintMachineInstrs("print-machineinstrs", cl::ValueOptional,
                    cl::desc("Print machine instrs"),
                    cl::value_desc("pass-name"), cl::init("option-unspecified"));
 
+static cl::opt<bool> EnableGlobalISelAbort(
+    "global-isel-abort", cl::Hidden,
+    cl::desc("Enable abort calls when \"global\" instruction selection "
+             "fails to lower/select an instruction"),
+    cl::init(true));
+
 // Temporary option to allow experimenting with MachineScheduler as a post-RA
 // scheduler. Targets can "properly" enable this with
 // substitutePass(&PostRASchedulerID, &PostMachineSchedulerID).
@@ -888,3 +894,10 @@ void TargetPassConfig::addBlockPlacement() {
       addPass(&MachineBlockPlacementStatsID);
   }
 }
+
+//===---------------------------------------------------------------------===//
+/// GlobalISel Configuration
+//===---------------------------------------------------------------------===//
+bool TargetPassConfig::isGlobalISelAbortEnabled() const {
+  return EnableGlobalISelAbort;
+}