[llvm] [ARM][Thumb2] Mark BTI-clearing instructions as scheduling region boundaries (PR #79173)

[Ramkumar Ramachandra via llvm-commits]

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@@ -0,0 +1,166 @@
+# RUN: llc -o - -run-pass=machine-scheduler -misched=shuffle %s | FileCheck %s
+# RUN: llc -o - -run-pass=postmisched %s | FileCheck %s
+
+--- |
+  target datalayout = "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64"
+  target triple = "thumbv8.1m.main-arm-none-eabi"
+
+  define i32 @foo_bti() #0 {
+  entry:
+    ret i32 0
+  }
+
+  define i32 @foo_pac() #0 {
+  entry:
+    ret i32 0
+  }
+
+  define i32 @foo_pacbti() #0 {
+  entry:
+    ret i32 0
+  }
+
+  define i32 @foo_setjmp() #0 {
+  entry:
+    ret i32 0
+  if.then:
+    ret i32 0
+  }
+
+  define i32 @foo_sg() #0 {
+  entry:
+    ret i32 0
+  }
+
+  declare i32 @setjmp(ptr noundef) #1
+  declare void @longjmp(ptr noundef, i32 noundef) #2
+
+  attributes #0 = { "frame-pointer"="all" "target-cpu"="cortex-m55" "target-features"="+armv8.1-m.main" }
+  attributes #1 = { nounwind returns_twice "frame-pointer"="all" "target-cpu"="cortex-m55" "target-features"="+armv8.1-m.main" }
+  attributes #2 = { noreturn nounwind "frame-pointer"="all" "target-cpu"="cortex-m55" "target-features"="+armv8.1-m.main" }
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artagnon wrote:

These attributes don't seem to be necessary. You can pass the target to llc, and the relevant ones can be added inline.

https://github.com/llvm/llvm-project/pull/79173