Test showing incorrect codegen

Author: ostannard

llvm/test/CodeGen/AArch64/memtag-merge-writeback.mir

@@ -0,0 +1,140 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 5
+# RUN: llc -mtriple aarch64-none-elf -mattr=+mte --run-pass=aarch64-ldst-opt %s -o - | FileCheck %s
+
+## When generating code with sanitize_memtag, we make use of the fact that the
+## sp+imm forms of many load and store instructions are not tag-checked, so we
+## can use SP directly instead of needing a register holding the tagged
+## pointer. However, this isn't true for the writeback versions of the
+## instructions, so we can't fold ADDs and SUBs into them in
+## AArch64LoadStoreOptimizer. This would be possible in cases where the
+## loads/stores only access untagged stack slots, but that information isn't
+## easily available after frame index elimination.
+
+--- |
+  define void @pre_index() {
+  entry:
+    ret void
+  }
+  define void @pre_index_memtag() sanitize_memtag {
+  entry:
+    ret void
+  }
+  define void @pre_index_memtag_not_sp() sanitize_memtag {
+  entry:
+    ret void
+  }
+  define void @post_index() {
+  entry:
+    ret void
+  }
+  define void @post_index_memtag() sanitize_memtag {
+  entry:
+    ret void
+  }
+  define void @post_index_memtag_not_sp() sanitize_memtag {
+  entry:
+    ret void
+  }
+...
+---
+name:            pre_index
+body:             |
+  bb.0.entry:
+    liveins: $x0
+
+    ; CHECK-LABEL: name: pre_index
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: $sp = frame-setup SUBXri $sp, 16, 0
+    ; CHECK-NEXT: early-clobber $sp = STRXpre killed renamable $x0, $sp, 16
+    ; CHECK-NEXT: RET undef $lr
+    $sp = frame-setup SUBXri $sp, 16, 0
+    STRXui killed renamable $x0, $sp, 2
+    $sp = ADDXri $sp, 16, 0
+    RET undef $lr
+...
+---
+name:            pre_index_memtag
+body:             |
+  bb.0.entry:
+    liveins: $x0
+
+    ; CHECK-LABEL: name: pre_index_memtag
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: $sp = frame-setup SUBXri $sp, 16, 0
+    ; CHECK-NEXT: early-clobber $sp = STRXpre killed renamable $x0, $sp, 16
+    ; CHECK-NEXT: RET undef $lr
+    $sp = frame-setup SUBXri $sp, 16, 0
+    STRXui killed renamable $x0, $sp, 2
+    $sp = ADDXri $sp, 16, 0
+    RET undef $lr
+...
+---
+name:            pre_index_memtag_not_sp
+body:             |
+  bb.0.entry:
+    liveins: $x0, $x1
+
+    ; CHECK-LABEL: name: pre_index_memtag_not_sp
+    ; CHECK: liveins: $x0, $x1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: $x1 = frame-setup SUBXri $x1, 16, 0
+    ; CHECK-NEXT: early-clobber $x1 = STRXpre killed renamable $x0, $x1, 16
+    ; CHECK-NEXT: RET undef $lr, implicit $x1
+    $x1 = frame-setup SUBXri $x1, 16, 0
+    STRXui killed renamable $x0, $x1, 2
+    $x1 = ADDXri $x1, 16, 0
+    RET undef $lr, implicit $x1
+...
+---
+name:            post_index
+body:             |
+  bb.0.entry:
+    liveins: $x0
+
+    ; CHECK-LABEL: name: post_index
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: $sp = frame-setup SUBXri $sp, 16, 0
+    ; CHECK-NEXT: early-clobber $sp = STRXpost killed renamable $x0, $sp, 16
+    ; CHECK-NEXT: RET undef $lr
+    $sp = frame-setup SUBXri $sp, 16, 0
+    STRXui killed renamable $x0, $sp, 0
+    $sp = ADDXri $sp, 16, 0
+    RET undef $lr
+...
+---
+name:            post_index_memtag
+body:             |
+  bb.0.entry:
+    liveins: $x0
+
+    ; CHECK-LABEL: name: post_index_memtag
+    ; CHECK: liveins: $x0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: $sp = frame-setup SUBXri $sp, 16, 0
+    ; CHECK-NEXT: early-clobber $sp = STRXpost killed renamable $x0, $sp, 16
+    ; CHECK-NEXT: RET undef $lr
+    $sp = frame-setup SUBXri $sp, 16, 0
+    STRXui killed renamable $x0, $sp, 0
+    $sp = ADDXri $sp, 16, 0
+    RET undef $lr
+...
+---
+name:            post_index_memtag_not_sp
+body:             |
+  bb.0.entry:
+    liveins: $x0, $x1
+
+    ; CHECK-LABEL: name: post_index_memtag_not_sp
+    ; CHECK: liveins: $x0, $x1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: $x1 = frame-setup SUBXri $x1, 16, 0
+    ; CHECK-NEXT: early-clobber $x1 = STRXpost killed renamable $x0, $x1, 16
+    ; CHECK-NEXT: RET undef $lr, implicit $x1
+    $x1 = frame-setup SUBXri $x1, 16, 0
+    STRXui killed renamable $x0, $x1, 0
+    $x1 = ADDXri $x1, 16, 0
+    RET undef $lr, implicit $x1
+...