37 lines
1.1 KiB
LLVM
37 lines
1.1 KiB
LLVM
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; RUN: llc -mtriple=thumbv7-linux-gnueabi -o - %s | FileCheck %s
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; This alloca is just large enough that FrameLowering decides it needs a frame
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; to guarantee access, based on the range of ldrex.
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; The actual alloca size is a bit of black magic, unfortunately: the real
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; maximum accessible is 1020, but FrameLowering adds 16 bytes to its estimated
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; stack size just because so the alloca is not actually the what the limit gets
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; compared to. The important point is that we don't go up to ~4096, which is the
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; default with no strange instructions.
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define void @test_large_frame() {
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; CHECK-LABEL: test_large_frame:
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; CHECK: push
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; CHECK: sub.w sp, sp, #1008
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%ptr = alloca i32, i32 252
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%addr = getelementptr i32, i32* %ptr, i32 1
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call i32 @llvm.arm.ldrex.p0i32(i32* %addr)
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ret void
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}
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; This alloca is just is just the other side of the limit, so no frame
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define void @test_small_frame() {
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; CHECK-LABEL: test_small_frame:
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; CHECK-NOT: push
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; CHECK: sub.w sp, sp, #1004
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%ptr = alloca i32, i32 251
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%addr = getelementptr i32, i32* %ptr, i32 1
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call i32 @llvm.arm.ldrex.p0i32(i32* %addr)
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ret void
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}
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declare i32 @llvm.arm.ldrex.p0i32(i32*)
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