[llvm] [BOLT] Ensure remember and restore CFIs are in the same list (PR #144348)

[Paschalis Mpeis via llvm-commits]

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@@ -0,0 +1,69 @@
+// This test checks that BOLT does not split remember and restore CFI states
+// into different lists, which would cause an assertion failure.
+
+# RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o
+# RUN: %clang %cflags %t.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt %t.exe -o %t.bolt 2>&1 | FileCheck %s
+
+# CHECK: BOLT-INFO: Target architecture: aarch64
+# CHECK: BOLT-INFO: enabling relocation mode
+# CHECK-NOT: llvm-bolt:
+# CHECK: BOLT-INFO: Starting stub-insertion pass
+
+.text
+.global main
+.type main, %function
+
+main:
+.cfi_startproc
+.cfi_def_cfa_offset 16
+.cfi_offset x30, -8
+.cfi_remember_state
+mov	x9, #0x3ff0000000000000
+mov	x8, x0
+stp	x30, x9, [sp, #-0x10]!
+add	x3, sp, #0x8
+mov	x0, x1
+mov	x1, x2
+mov	x2, x8
+bl main
+fcmp	d0, #0.0
+b.ne main+0x34
+
+mov	w0, wzr
+ldr	x30, [sp], #0x10
+.cfi_def_cfa_offset 0
+.cfi_restore x30
+
+ret
+.cfi_restore_state
+.cfi_remember_state
+
+fmov	x8, d0
+mov	x9, #0x7ff0000000000000
+and	x8, x8, #0x7fffffffffffffff
+cmp	x8, x9
+b.lt main+0x5c
+fcmp	d0, #0.0
+mov	w8, #-0x1
+csinc	w0, w8, wzr, le
+ldr	x30, [sp], #0x10
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paschalis-mpeis wrote:

Thanks for the test! Can you please minimize it a bit more?

You can drop the majority of instructions that don't contribute to the test and keep only a few dummy ones like `mov, x0 xzr`. Some of the blocks could be dropped as well.

Once cleaned up, you can replace the hardcoded relative addresses to temp labels. Maybe `--asum-dump` could give you hints on where to place those labels, alternatively `objdump` would do.

https://github.com/llvm/llvm-project/pull/144348