[PATCH] D66459: Make ShrinkWrap more consistent.

[zuojian lin via Phabricator via llvm-commits]

linzj created this revision.
linzj added a reviewer: chill.
Herald added subscribers: llvm-commits, hiraditya.
Herald added a project: LLVM.

When see a terminator like tail call, useOrDefCSROrFI should return false Immediately.
When checking if a register is a CSR, useOrDefCSROrFI should use getCurrentCSRs.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D66459

Files:
  llvm/lib/CodeGen/ShrinkWrap.cpp


Index: llvm/lib/CodeGen/ShrinkWrap.cpp
===================================================================
--- llvm/lib/CodeGen/ShrinkWrap.cpp
+++ llvm/lib/CodeGen/ShrinkWrap.cpp
@@ -272,6 +272,8 @@
     LLVM_DEBUG(dbgs() << "Frame instruction: " << MI << '\n');
     return true;
   }
+  if (MI.isTerminator())
+    return false;
   for (const MachineOperand &MO : MI.operands()) {
     bool UseOrDefCSR = false;
     if (MO.isReg()) {
@@ -287,8 +289,8 @@
       // separately. An SP mentioned by a call instruction, we can ignore,
       // though, as it's harmless and we do not want to effectively disable tail
       // calls by forcing the restore point to post-dominate them.
-      UseOrDefCSR = (!MI.isCall() && PhysReg == SP) ||
-                    RCI.getLastCalleeSavedAlias(PhysReg);
+      UseOrDefCSR =
+          (!MI.isCall() && PhysReg == SP) || getCurrentCSRs(RS).count(PhysReg);
     } else if (MO.isRegMask()) {
       // Check if this regmask clobbers any of the CSRs.
       for (unsigned Reg : getCurrentCSRs(RS)) {


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D66459.216037.patch
Type: text/x-patch
Size: 1041 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20190820/25ed103d/attachment.bin>