2e47b93fd2
When -mno-movt is passed to Clang, the ARM codegen correctly avoids movt/movw pairs to take the address of __stack_chk_guard in the stack protector code emitted into the function pro- and epilogues. However, the Thumb2 codegen fails to do so, and happily emits movw/movt pairs unless it is generating an ELF binary and the symbol might be in a different DSO. Let's incorporate a check for useMovt() in the logic here, so movt/movw are never emitted when -mno-movt is specified. Suggestions welcome for how/where to add a test case for this. Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
33 lines
874 B
LLVM
33 lines
874 B
LLVM
; RUN: llc -relocation-model=static -mattr=+no-movt < %s | FileCheck %s
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target triple = "thumbv7a-linux-gnueabi"
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define i32 @test1() #0 {
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; CHECK-LABEL: test1:
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; CHECK: @ %bb.0:
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; CHECK-NEXT: push {r7, lr}
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; CHECK-NEXT: sub.w sp, sp, #1032
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; CHECK-NEXT: ldr r0, .LCPI0_0
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; CHECK-NEXT: ldr r0, [r0]
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; CHECK-NEXT: str.w r0, [sp, #1028]
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; CHECK-NEXT: add r0, sp, #4
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; CHECK-NEXT: bl foo
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; CHECK-NEXT: ldr.w r0, [sp, #1028]
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; CHECK-NEXT: ldr r1, .LCPI0_0
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; CHECK-NEXT: ldr r1, [r1]
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; CHECK-NEXT: cmp r1, r0
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; CHECK-NEXT: ittt eq
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; CHECK-NEXT: moveq r0, #0
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; CHECK-NEXT: addeq.w sp, sp, #1032
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; CHECK-NEXT: popeq {r7, pc}
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; CHECK-NEXT: .LBB0_1:
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; CHECK-NEXT: bl __stack_chk_fail
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%a1 = alloca [256 x i32], align 4
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call void @foo(ptr %a1) #3
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ret i32 0
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}
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declare void @foo(ptr)
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attributes #0 = { nounwind sspstrong }
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