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[BOLT][AArch64] Fixes assertion errors occurred when perf2bolt was ex…
…ecuted (llvm#83394) BOLT only checks for the most common indirect branch pattern during the branch analyzation. Extended the logic with two other indirect patterns which slightly differ from the expected one. Those patterns may be hit when statically linking libc (pattern 2 requires 'lld' linker). As a workaround mark them as UNKNOWN branch for now. Fixes: llvm#83114
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// Test how BOLT handles indirect branch sequence of instructions in | ||
// AArch64MCPlus builder. | ||
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// clang-format off | ||
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// REQUIRES: system-linux | ||
// RUN: llvm-mc -filetype=obj -triple aarch64-unknown-unknown %s -o %t.o | ||
// RUN: %clang %cflags --target=aarch64-unknown-linux %t.o -o %t.exe -Wl,-q | ||
// RUN: llvm-bolt %t.exe -o %t.bolt --print-cfg --strict\ | ||
// RUN: -v=1 2>&1 | FileCheck %s | ||
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// Pattern 1: there is no shift amount after the 'add' instruction. | ||
// | ||
// adr x6, 0x219fb0 <sigall_set+0x88> | ||
// add x6, x6, x14, lsl #2 | ||
// ldr w7, [x6] | ||
// add x6, x6, w7, sxtw => no shift amount | ||
// br x6 | ||
// | ||
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// Pattern 2: nop/adr pair is used in place of adrp/add | ||
// | ||
// nop => nop/adr instead of adrp/add | ||
// adr x13, 0x215a18 <_nl_value_type_LC_COLLATE+0x50> | ||
// ldrh w13, [x13, w12, uxtw #1] | ||
// adr x12, 0x247b30 <__gettextparse+0x5b0> | ||
// add x13, x12, w13, sxth #2 | ||
// br x13 | ||
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.section .text | ||
.align 4 | ||
.globl _start | ||
.type _start, %function | ||
_start: | ||
bl test1 | ||
bl test2 | ||
// mov x0, #4 | ||
// mov w8, #93 | ||
// svc #0 | ||
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// Pattern 1 | ||
// CHECK: BOLT-WARNING: Failed to match indirect branch: ShiftVAL != 2 | ||
.globl test1 | ||
.type test1, %function | ||
test1: | ||
mov x1, #0 | ||
adr x3, datatable | ||
add x3, x3, x1, lsl #2 | ||
ldr w2, [x3] | ||
add x3, x3, w2, sxtw | ||
br x3 | ||
test1_0: | ||
ret | ||
test1_1: | ||
ret | ||
test1_2: | ||
ret | ||
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// Pattern 2 | ||
// CHECK: BOLT-WARNING: Failed to match indirect branch: nop/adr instead of adrp/add | ||
.globl test2 | ||
.type test2, %function | ||
test2: | ||
nop | ||
adr x3, jump_table | ||
ldrh w3, [x3, x1, lsl #1] | ||
adr x1, test2_0 | ||
add x3, x1, w3, sxth #2 | ||
br x3 | ||
test2_0: | ||
ret | ||
test2_1: | ||
ret | ||
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.section .rodata,"a",@progbits | ||
datatable: | ||
.word test1_0-datatable | ||
.word test1_1-datatable | ||
.word test1_2-datatable | ||
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jump_table: | ||
.hword (test2_0-test2_0)>>2 | ||
.hword (test2_1-test2_0)>>2 |