[XRay][CodeGen][PowerPC] Fix tail exit codegen for XRay in PPC
Summary:
This fixes code-gen for XRay in PPC. The regression wasn't caught by
codegen tests which we add in this change.
What happened was the following:
- For tail exits, we used to unconditionally prepend the returns/exits
with a pseudo-instruction that gets lowered to the instrumentation
sled (and leave the actual return/exit instruction as-is).
- Changes to the XRay instrumentation pass caused the tail exits to
suddenly also emit the tail exit pseudo-instruction, since the check
for whether a return instruction was also a call instruction meant it
was a tail exit instruction.
- None of the tests caught the regression either due to non-existent
tests, or the tests being disabled/removed for continuous breakage.
This change re-introduces some of the basic tests and verifies that
we're back to a state that allows the back-end to generate appropriate
XRay instrumented binaries for PPC in the presence of tail exits.
Reviewers: echristo, timshen
Subscribers: nemanjai, kbarton, llvm-commits
Differential Revision: https://reviews.llvm.org/D37570
llvm-svn: 312772
diff --git a/llvm/lib/CodeGen/XRayInstrumentation.cpp b/llvm/lib/CodeGen/XRayInstrumentation.cpp
index 0b4c6e5..e6b6582 100644
--- a/llvm/lib/CodeGen/XRayInstrumentation.cpp
+++ b/llvm/lib/CodeGen/XRayInstrumentation.cpp
@@ -14,8 +14,8 @@
//
//===---------------------------------------------------------------------===//
-#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Triple.h"
#include "llvm/CodeGen/MachineBasicBlock.h"
#include "llvm/CodeGen/MachineDominators.h"
@@ -109,22 +109,13 @@
void XRayInstrumentation::prependRetWithPatchableExit(
MachineFunction &MF, const TargetInstrInfo *TII) {
- for (auto &MBB : MF) {
- for (auto &T : MBB.terminators()) {
- unsigned Opc = 0;
+ for (auto &MBB : MF)
+ for (auto &T : MBB.terminators())
if (T.isReturn()) {
- Opc = TargetOpcode::PATCHABLE_FUNCTION_EXIT;
+ // Prepend the return instruction with PATCHABLE_FUNCTION_EXIT.
+ BuildMI(MBB, T, T.getDebugLoc(),
+ TII->get(TargetOpcode::PATCHABLE_FUNCTION_EXIT));
}
- if (TII->isTailCall(T)) {
- Opc = TargetOpcode::PATCHABLE_TAIL_CALL;
- }
- if (Opc != 0) {
- // Prepend the return instruction with PATCHABLE_FUNCTION_EXIT or
- // PATCHABLE_TAIL_CALL .
- BuildMI(MBB, T, T.getDebugLoc(), TII->get(Opc));
- }
- }
- }
}
bool XRayInstrumentation::runOnMachineFunction(MachineFunction &MF) {
@@ -143,7 +134,7 @@
// Count the number of MachineInstr`s in MachineFunction
int64_t MICount = 0;
- for (const auto& MBB : MF)
+ for (const auto &MBB : MF)
MICount += MBB.size();
// Check if we have a loop.