[GlobalISel] Make EnableGlobalISel always set when GISel is enabled

Change meaning of TargetOptions::EnableGlobalISel. The flag was
previously set only when a target switched on GlobalISel but it is now
always set when the GlobalISel pipeline is enabled. This makes the flag
consistent with TargetOptions::EnableFastISel and allows its use in
other parts of the compiler to determine when GlobalISel is enabled.

The EnableGlobalISel flag had previouly only one use in
TargetPassConfig::isGlobalISelAbortEnabled(). The method used its value
to determine if GlobalISel was enabled by a target and returned false in
such a case. To preserve the current behaviour, a new flag
TargetOptions::GlobalISelAbort is introduced to separately record the
abort behaviour.

Differential Revision: https://reviews.llvm.org/D54518

llvm-svn: 347861

1 files changed, 3 insertions, 1 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
index 6dacbe8a9fe..c6073a59654 100644
--- a/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
+++ b/llvm/lib/Target/AArch64/AArch64TargetMachine.cpp
@@ -275,8 +275,10 @@ AArch64TargetMachine::AArch64TargetMachine(const Target &T, const Triple &TT,
   }
 
   // Enable GlobalISel at or below EnableGlobalISelAt0.
-  if (getOptLevel() <= EnableGlobalISelAtO)
+  if (getOptLevel() <= EnableGlobalISelAtO) {
     setGlobalISel(true);
+    setGlobalISelAbort(GlobalISelAbortMode::Disable);
+  }
 
   // AArch64 supports the MachineOutliner.
   setMachineOutliner(true);