[ARM] Add a baseline elf-preemption test

This is based on the RISC-V elf-preemption.ll (converted to opaque
pointers) and is useful for test coverage for the patch series starting
with D131392.

Author: arichardson

llvm/test/CodeGen/ARM/elf-preemption.ll

@@ -0,0 +1,192 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=armv7-linux-gnueabi -relocation-model=static < %s \
+; RUN:   | FileCheck %s --check-prefix=STATIC
+; RUN: llc -mtriple=armv7-linux-gnueabi -relocation-model=pic < %s \
+; RUN:   | FileCheck %s --check-prefix=PIC
+
+@preemptable_var = dso_preemptable global i32 42
+define ptr @get_preemptable_var() nounwind {
+; STATIC-LABEL: get_preemptable_var:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    movw r0, :lower16:preemptable_var
+; STATIC-NEXT:    movt r0, :upper16:preemptable_var
+; STATIC-NEXT:    bx lr
+;
+; PIC-LABEL: get_preemptable_var:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    ldr r0, .LCPI0_0
+; PIC-NEXT:  .LPC0_0:
+; PIC-NEXT:    ldr r0, [pc, r0]
+; PIC-NEXT:    bx lr
+; PIC-NEXT:    .p2align 2
+; PIC-NEXT:  @ %bb.1:
+; PIC-NEXT:  .LCPI0_0:
+; PIC-NEXT:  .Ltmp0:
+; PIC-NEXT:    .long preemptable_var(GOT_PREL)-((.LPC0_0+8)-.Ltmp0)
+  ret ptr @preemptable_var
+}
+
+@dsolocal_var = dso_local global i32 42
+define ptr @get_dsolocal_var() nounwind {
+; STATIC-LABEL: get_dsolocal_var:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    movw r0, :lower16:dsolocal_var
+; STATIC-NEXT:    movt r0, :upper16:dsolocal_var
+; STATIC-NEXT:    bx lr
+;
+; PIC-LABEL: get_dsolocal_var:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    ldr r0, .LCPI1_0
+; PIC-NEXT:  .LPC1_0:
+; PIC-NEXT:    add r0, pc, r0
+; PIC-NEXT:    bx lr
+; PIC-NEXT:    .p2align 2
+; PIC-NEXT:  @ %bb.1:
+; PIC-NEXT:  .LCPI1_0:
+; PIC-NEXT:    .long dsolocal_var-(.LPC1_0+8)
+  ret ptr @dsolocal_var
+}
+
+@weak_dsolocal_var = weak dso_local global i32 42
+define ptr @get_weak_dsolocal_var() nounwind {
+; STATIC-LABEL: get_weak_dsolocal_var:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    movw r0, :lower16:weak_dsolocal_var
+; STATIC-NEXT:    movt r0, :upper16:weak_dsolocal_var
+; STATIC-NEXT:    bx lr
+;
+; PIC-LABEL: get_weak_dsolocal_var:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    ldr r0, .LCPI2_0
+; PIC-NEXT:  .LPC2_0:
+; PIC-NEXT:    add r0, pc, r0
+; PIC-NEXT:    bx lr
+; PIC-NEXT:    .p2align 2
+; PIC-NEXT:  @ %bb.1:
+; PIC-NEXT:  .LCPI2_0:
+; PIC-NEXT:    .long weak_dsolocal_var-(.LPC2_0+8)
+  ret ptr @weak_dsolocal_var
+}
+
+@hidden_var = hidden global i32 42
+define ptr @get_hidden_var() nounwind {
+; STATIC-LABEL: get_hidden_var:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    movw r0, :lower16:hidden_var
+; STATIC-NEXT:    movt r0, :upper16:hidden_var
+; STATIC-NEXT:    bx lr
+;
+; PIC-LABEL: get_hidden_var:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    ldr r0, .LCPI3_0
+; PIC-NEXT:  .LPC3_0:
+; PIC-NEXT:    add r0, pc, r0
+; PIC-NEXT:    bx lr
+; PIC-NEXT:    .p2align 2
+; PIC-NEXT:  @ %bb.1:
+; PIC-NEXT:  .LCPI3_0:
+; PIC-NEXT:    .long hidden_var-(.LPC3_0+8)
+  ret ptr @hidden_var
+}
+
+@protected_var = protected global i32 42
+define ptr @get_protected_var() nounwind {
+; STATIC-LABEL: get_protected_var:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    movw r0, :lower16:protected_var
+; STATIC-NEXT:    movt r0, :upper16:protected_var
+; STATIC-NEXT:    bx lr
+;
+; PIC-LABEL: get_protected_var:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    ldr r0, .LCPI4_0
+; PIC-NEXT:  .LPC4_0:
+; PIC-NEXT:    add r0, pc, r0
+; PIC-NEXT:    bx lr
+; PIC-NEXT:    .p2align 2
+; PIC-NEXT:  @ %bb.1:
+; PIC-NEXT:  .LCPI4_0:
+; PIC-NEXT:    .long protected_var-(.LPC4_0+8)
+  ret ptr @protected_var
+}
+
+define dso_preemptable ptr @preemptable_func() nounwind {
+; STATIC-LABEL: preemptable_func:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    movw r0, :lower16:preemptable_func
+; STATIC-NEXT:    movt r0, :upper16:preemptable_func
+; STATIC-NEXT:    bx lr
+;
+; PIC-LABEL: preemptable_func:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    ldr r0, .LCPI5_0
+; PIC-NEXT:  .LPC5_0:
+; PIC-NEXT:    ldr r0, [pc, r0]
+; PIC-NEXT:    bx lr
+; PIC-NEXT:    .p2align 2
+; PIC-NEXT:  @ %bb.1:
+; PIC-NEXT:  .LCPI5_0:
+; PIC-NEXT:  .Ltmp1:
+; PIC-NEXT:    .long preemptable_func(GOT_PREL)-((.LPC5_0+8)-.Ltmp1)
+  ret ptr @preemptable_func
+}
+
+define dso_local ptr @dsolocal_func() nounwind {
+; STATIC-LABEL: dsolocal_func:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    movw r0, :lower16:dsolocal_func
+; STATIC-NEXT:    movt r0, :upper16:dsolocal_func
+; STATIC-NEXT:    bx lr
+;
+; PIC-LABEL: dsolocal_func:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    ldr r0, .LCPI6_0
+; PIC-NEXT:  .LPC6_0:
+; PIC-NEXT:    add r0, pc, r0
+; PIC-NEXT:    bx lr
+; PIC-NEXT:    .p2align 2
+; PIC-NEXT:  @ %bb.1:
+; PIC-NEXT:  .LCPI6_0:
+; PIC-NEXT:    .long dsolocal_func-(.LPC6_0+8)
+  ret ptr @dsolocal_func
+}
+
+define weak dso_local ptr @weak_dsolocal_func() nounwind {
+; STATIC-LABEL: weak_dsolocal_func:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    movw r0, :lower16:weak_dsolocal_func
+; STATIC-NEXT:    movt r0, :upper16:weak_dsolocal_func
+; STATIC-NEXT:    bx lr
+;
+; PIC-LABEL: weak_dsolocal_func:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    ldr r0, .LCPI7_0
+; PIC-NEXT:  .LPC7_0:
+; PIC-NEXT:    add r0, pc, r0
+; PIC-NEXT:    bx lr
+; PIC-NEXT:    .p2align 2
+; PIC-NEXT:  @ %bb.1:
+; PIC-NEXT:  .LCPI7_0:
+; PIC-NEXT:    .long weak_dsolocal_func-(.LPC7_0+8)
+  ret ptr @weak_dsolocal_func
+}
+
+;; call .Ldsolocal_func$local either resolves to a constant at assembly time
+;; or produces a relocation referencing a non-preemptible local symbol.
+define dso_local void @call_dsolocal_func() nounwind {
+; STATIC-LABEL: call_dsolocal_func:
+; STATIC:       @ %bb.0:
+; STATIC-NEXT:    .save {r11, lr}
+; STATIC-NEXT:    push {r11, lr}
+; STATIC-NEXT:    bl dsolocal_func
+; STATIC-NEXT:    pop {r11, pc}
+;
+; PIC-LABEL: call_dsolocal_func:
+; PIC:       @ %bb.0:
+; PIC-NEXT:    .save {r11, lr}
+; PIC-NEXT:    push {r11, lr}
+; PIC-NEXT:    bl dsolocal_func
+; PIC-NEXT:    pop {r11, pc}
+  call ptr @dsolocal_func()
+  ret void
+}