llvm-project/llvm/test/CodeGen/Thumb/large-stack.ll

81 lines
2.3 KiB
LLVM

; RUN: llc < %s -mtriple=thumb-apple-ios | FileCheck %s --check-prefix=CHECK --check-prefix=IOS
; RUN: llc < %s -mtriple=thumb-none-eabi | FileCheck %s --check-prefix=CHECK --check-prefix=EABI
; RUN: llc < %s -o %t -filetype=obj -mtriple=thumbv6-apple-ios
; RUN: llvm-objdump -triple=thumbv6-apple-ios -d %t | FileCheck %s --check-prefix=CHECK --check-prefix=IOS
; RUN: llc < %s -o %t -filetype=obj -mtriple=thumbv6-none-eabi
; RUN: llvm-objdump -triple=thumbv6-none-eabi -d %t | FileCheck %s --check-prefix=CHECK --check-prefix=EABI
; Largest stack for which a single tADDspi/tSUBspi is enough
define void @test1() {
; CHECK-LABEL: test1:
; CHECK: sub sp, #508
; CHECK: add sp, #508
%tmp = alloca [ 508 x i8 ] , align 4
ret void
}
; Largest stack for which three tADDspi/tSUBspis are enough
define void @test100() {
; CHECK-LABEL: test100:
; CHECK: sub sp, #508
; CHECK: sub sp, #508
; CHECK: sub sp, #508
; EABI: add sp, #508
; EABI: add sp, #508
; EABI: add sp, #508
; IOS: subs r4, r7, #4
; IOS: mov sp, r4
%tmp = alloca [ 1524 x i8 ] , align 4
ret void
}
; Smallest stack for which we use a constant pool
define void @test2() {
; CHECK-LABEL: test2:
; CHECK: ldr r0,
; CHECK: add sp, r0
; EABI: ldr r0,
; EABI: add sp, r0
; IOS: subs r4, r7, #4
; IOS: mov sp, r4
%tmp = alloca [ 1528 x i8 ] , align 4
ret void
}
define i32 @test3() {
; CHECK-LABEL: test3:
; CHECK: ldr r1,
; CHECK: add sp, r1
; CHECK: ldr r1,
; CHECK: add r1, sp
; EABI: ldr r1,
; EABI: add sp, r1
; IOS: subs r4, r7, #4
; IOS: mov sp, r4
%retval = alloca i32, align 4
%tmp = alloca i32, align 4
%a = alloca [805306369 x i8], align 16
store i32 0, i32* %tmp
%tmp1 = load i32, i32* %tmp
ret i32 %tmp1
}
; Here, the adds get optimized out because they are dead, but the calculation
; of the address of stack_a is dead but not optimized out. When the address
; calculation gets expanded to two instructions, we need to avoid reading a
; dead register.
; No CHECK lines (just test for crashes), as we hope this will be optimised
; better in future.
define i32 @test4() {
entry:
%stack_a = alloca i8, align 1
%stack_b = alloca [256 x i32*], align 4
%int = ptrtoint i8* %stack_a to i32
%add = add i32 %int, 1
br label %block2
block2:
%add2 = add i32 %add, 1
ret i32 0
}