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38133c4e94
On SparcV8, it was previously the case that a variable-sized alloca might overlap by 4-bytes the last fixed stack variable, effectively because 92 (the number of bytes reserved for the register spill area) != 96 (the offset added to SP for where to start a DYNAMIC_STACKALLOC). It's not as simple as changing 96 to 92, because variables that should be 8-byte aligned would then be misaligned. For now, simply increase the allocation size by 8 bytes for each dynamic allocation -- wastes space, but at least doesn't overlap. As the large comment says, doing this more efficiently will require larger changes in llvm. Also adds some test cases showing that we continue to not support dynamic stack allocation and over-alignment in the same function. llvm-svn: 285131
21 lines
750 B
LLVM
21 lines
750 B
LLVM
; RUN: llc -march=sparc < %s | FileCheck %s
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declare void @stack_realign_helper(i32 %a, i32* %b)
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;; This is a function where we have a local variable of 64-byte
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;; alignment. We want to see that the stack is aligned (the initial
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;; andn), that the local var is accessed via stack pointer (to %o1), and that
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;; the argument is accessed via frame pointer not stack pointer (to %o0).
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;; CHECK-LABEL: stack_realign:
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;; CHECK: andn %sp, 63, %sp
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;; CHECK-NEXT: ld [%fp+92], %o0
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;; CHECK-NEXT: call stack_realign_helper
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;; CHECK-NEXT: add %sp, 128, %o1
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define void @stack_realign(i32 %a, i32 %b, i32 %c, i32 %d, i32 %e, i32 %f, i32 %g) {
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entry:
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%aligned = alloca i32, align 64
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call void @stack_realign_helper(i32 %g, i32* %aligned)
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ret void
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}
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