AMDGPU/GlobalISel: Skip DAG hack passes on selected functions

The way fallback to SelectionDAG works is somewhat surprising to
me. When the fallback path is enabled, the entire set of SelectionDAG
selector passes is added to the pass pipeline, and each one needs to
check if the function was selected. This results in the surprising
behavior of running SIFixSGPRCopies for example, but only if
-global-isel-abort=2 is used.

SIAddIMGInitPass is also added in addInstSelector, but I'm not sure
why we have this pass or if it should be added somewhere else for
GlobalISel.

diff --git a/llvm/lib/Target/AMDGPU/SIFixSGPRCopies.cpp b/llvm/lib/Target/AMDGPU/SIFixSGPRCopies.cpp
index 914d2a5..f067e96 100644 (file)
--- a/llvm/lib/Target/AMDGPU/SIFixSGPRCopies.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFixSGPRCopies.cpp
@@ -587,6 +587,11 @@ static bool hoistAndMergeSGPRInits(unsigned Reg,
 }
 
 bool SIFixSGPRCopies::runOnMachineFunction(MachineFunction &MF) {
+  // Only need to run this in SelectionDAG path.
+  if (MF.getProperties().hasProperty(
+        MachineFunctionProperties::Property::Selected))
+    return false;
+
   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
   MRI = &MF.getRegInfo();
   TRI = ST.getRegisterInfo();

diff --git a/llvm/lib/Target/AMDGPU/SIFixupVectorISel.cpp b/llvm/lib/Target/AMDGPU/SIFixupVectorISel.cpp
index a011929..8e3402b 100644 (file)
--- a/llvm/lib/Target/AMDGPU/SIFixupVectorISel.cpp
+++ b/llvm/lib/Target/AMDGPU/SIFixupVectorISel.cpp
@@ -217,6 +217,11 @@ static bool fixupGlobalSaddr(MachineBasicBlock &MBB,
 }
 
 bool SIFixupVectorISel::runOnMachineFunction(MachineFunction &MF) {
+  // Only need to run this in SelectionDAG path.
+  if (MF.getProperties().hasProperty(
+        MachineFunctionProperties::Property::Selected))
+    return false;
+
   if (skipFunction(MF.getFunction()))
     return false;
 

diff --git a/llvm/lib/Target/AMDGPU/SILowerI1Copies.cpp b/llvm/lib/Target/AMDGPU/SILowerI1Copies.cpp
index 1d45e62..236a24a 100644 (file)
--- a/llvm/lib/Target/AMDGPU/SILowerI1Copies.cpp
+++ b/llvm/lib/Target/AMDGPU/SILowerI1Copies.cpp
@@ -452,6 +452,11 @@ static unsigned insertUndefLaneMask(MachineBasicBlock &MBB) {
 /// all others, because phi lowering looks through copies and can therefore
 /// often make copy lowering unnecessary.
 bool SILowerI1Copies::runOnMachineFunction(MachineFunction &TheMF) {
+  // Only need to run this in SelectionDAG path.
+  if (TheMF.getProperties().hasProperty(
+        MachineFunctionProperties::Property::Selected))
+    return false;
+
   MF = &TheMF;
   MRI = &MF->getRegInfo();
   DT = &getAnalysis<MachineDominatorTree>();