AMDGPU: Change fdiv lowering based on !fpmath metadata

If 2.5 ulp is acceptable, denormals are not required, and
isn't a reciprocal which will already be handled, replace
with a faster fdiv.

Simplify the lowering tests by using per function
subtarget features.

llvm-svn: 276051

1 files changed, 8 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index 3e53f52c689..b2d4e1144c7 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -309,6 +309,7 @@ public:
   ScheduleDAGInstrs *
   createMachineScheduler(MachineSchedContext *C) const override;
 
+  void addIRPasses() override;
   bool addPreISel() override;
   void addMachineSSAOptimization() override;
   bool addInstSelector() override;
@@ -499,6 +500,13 @@ void GCNPassConfig::addMachineSSAOptimization() {
   addPass(&DeadMachineInstructionElimID);
 }
 
+void GCNPassConfig::addIRPasses() {
+  // TODO: May want to move later or split into an early and late one.
+  addPass(createAMDGPUCodeGenPreparePass(&getGCNTargetMachine()));
+
+  AMDGPUPassConfig::addIRPasses();
+}
+
 bool GCNPassConfig::addInstSelector() {
   AMDGPUPassConfig::addInstSelector();
   addPass(createSILowerI1CopiesPass());