[llvm] [BOLT]Identify indirect call (PR #123305)

[Paschalis Mpeis via llvm-commits]

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@@ -0,0 +1,52 @@
+## This test checks that indirect tail call is properly identified by BOLT on aarch64.
+# REQUIRES: system-linux
+
+# RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o
+# RUN: %clang %cflags -O0 %t.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt --print-all --print-only=indirect  \
+# RUN: %t.exe -o %t.bolt | FileCheck %s
+
+#CHECK: Binary Function "indirect" after building cfg {
+#CHECK-NOT: # UNKNOWN CONTROL FLOW
+#CHECK: End of Function "indirect"
+	.text
+	.global	indirect
+	.type	indirect, %function
+indirect:
+.LFB0:
+	.cfi_startproc
+	stp	x29, x30, [sp, -16]!
+	.cfi_def_cfa_offset 16
+	.cfi_offset 29, -16
+	.cfi_offset 30, -8
+	mov	w3, w1
+	add	w1, w0, w1
+	add	w5, w1, w1, lsr 31
+	tst	x1, 1
+	asr	w5, w5, 1
+	csel	w1, w1, w5, eq
+	cmp	w0, w3
+	beq	.L3
+	mov	w0, w3
+	mov	x16, x2
+	ldp	x29, x30, [sp], 16
+	.cfi_restore 30
+	.cfi_restore 29
+	.cfi_def_cfa_offset 0
+	br	x16
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paschalis-mpeis wrote:

Maybe could add another function variant that has a few non-stack-changing instructions between `OpDefCfaOffset 0` and the branch?

https://github.com/llvm/llvm-project/pull/123305