[PATCH] D100996: [AArch64] Fix for BTI landing pad insertion with PAC-RET+bkey.

[Daniel Kiss via Phabricator via llvm-commits]

danielkiss created this revision.
danielkiss added reviewers: tamas.petz, pbarrio, momchil.velikov, eugenis.
Herald added subscribers: hiraditya, kristof.beyls.
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EMITBKEY is emitted for PAC-RET+bkey, which is a pseudo instruction.
Here we should ignore all non machine instructions.

PR: 49957


https://reviews.llvm.org/D100996

Files:
  llvm/lib/Target/AArch64/AArch64BranchTargets.cpp
  llvm/test/CodeGen/AArch64/sign-return-address.ll


Index: llvm/test/CodeGen/AArch64/sign-return-address.ll
===================================================================
--- llvm/test/CodeGen/AArch64/sign-return-address.ll
+++ llvm/test/CodeGen/AArch64/sign-return-address.ll
@@ -122,3 +122,33 @@
 define i32 @leaf_sign_all_v83_b_key(i32 %x) "sign-return-address"="all" "target-features"="+v8.3a" "sign-return-address-key"="b_key" {
   ret i32 %x
 }
+
+; CHECK-LABEL: @leaf_sign_all_a_key_bti
+; CHECK-NOT:   hint #34
+; CHECK:       hint #25
+; CHECK:       hint #29
+; CHECK-V83A:  paciasp
+; CHECK-V83A:  retaa
+define i32 @leaf_sign_all_a_key_bti(i32 %x) "sign-return-address"="all" "sign-return-address-key"="a_key" "branch-target-enforcement"="true"{
+  ret i32 %x
+}
+
+; CHECK-LABEL: @leaf_sign_all_b_key_bti
+; CHECK-NOT:   hint #34
+; CHECK:       hint #27
+; CHECK:       hint #31
+; CHECK-V83A:  pacibsp
+; CHECK-V83A:  retab
+define i32 @leaf_sign_all_b_key_bti(i32 %x) "sign-return-address"="all" "sign-return-address-key"="b_key" "branch-target-enforcement"="true"{
+  ret i32 %x
+}
+
+; CHECK-LABEL: @leaf_sign_all_v83_b_key_bti
+; CHECK-NOT:   hint #34
+; CHECK: pacibsp
+; CHECK-NOT: ret
+; CHECK: retab
+; CHECK-NOT: ret
+define i32 @leaf_sign_all_v83_b_key_bti(i32 %x) "sign-return-address"="all" "target-features"="+v8.3a" "sign-return-address-key"="b_key" "branch-target-enforcement"="true" {
+  ret i32 %x
+}
Index: llvm/lib/Target/AArch64/AArch64BranchTargets.cpp
===================================================================
--- llvm/lib/Target/AArch64/AArch64BranchTargets.cpp
+++ llvm/lib/Target/AArch64/AArch64BranchTargets.cpp
@@ -121,8 +121,10 @@
 
   auto MBBI = MBB.begin();
 
-  // Skip the meta instuctions, those will be removed anyway.
-  for (; MBBI != MBB.end() && MBBI->isMetaInstruction(); ++MBBI)
+  // Skip the meta and pseudo instructions, those will be removed or won't emit
+  // machine code. EMITBKEY is a pseudo instruction.
+  for (; MBBI != MBB.end() && (MBBI->isMetaInstruction() || MBBI->isPseudo());
+       ++MBBI)
     ;
 
   // SCTLR_EL1.BT[01] is set to 0 by default which means


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