153 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			153 lines
		
	
	
		
			4.2 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: llc -mtriple=thumbv7m-none-eabi -o - %s | FileCheck %s
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| 
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| declare void @foo()
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| 
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| ; Leaf function, no frame so no need for a frame pointer.
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| define void @leaf() {
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| ; CHECK-LABEL: leaf:
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| ; CHECK-NOT: push
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| ; CHECK-NOT: sp
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| ; CHECK-NOT: pop
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| ; CHECK: bx lr
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|   ret void
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| }
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| 
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| ; Leaf function, frame pointer is requested but we don't need any stack frame,
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| ; so don't create a frame pointer.
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| define void @leaf_nofpelim() "frame-pointer"="all" {
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| ; CHECK-LABEL: leaf_nofpelim:
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| ; CHECK-NOT: push
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| ; CHECK-NOT: sp
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| ; CHECK-NOT: pop
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| ; CHECK: bx lr
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|   ret void
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| }
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| 
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| ; Leaf function, frame pointer is requested and we need a stack frame, so we
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| ; need to use a frame pointer.
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| define void @leaf_lowreg_nofpelim() "frame-pointer"="all" {
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| ; CHECK-LABEL: leaf_lowreg_nofpelim:
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| ; CHECK: push {r4, r6, r7, lr}
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| ; CHECK: add r7, sp, #8
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| ; CHECK: pop {r4, r6, r7, pc}
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|   call void asm sideeffect "", "~{r4}" ()
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|   ret void
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| }
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| 
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| ; Leaf function, frame pointer is requested and we need a stack frame, so we
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| ; need to use a frame pointer. A high register is pushed to the stack, so we
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| ; must use two push/pop instructions to ensure that fp and sp are adjacent on
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| ; the stack.
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| define void @leaf_highreg_nofpelim() "frame-pointer"="all" {
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| ; CHECK-LABEL: leaf_highreg_nofpelim:
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| ; CHECK: push {r6, r7, lr}
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| ; CHECK: add r7, sp, #4
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| ; CHECK: str r8, [sp, #-4]!
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| ; CHECK: ldr r8, [sp], #4
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| ; CHECK: pop {r6, r7, pc}
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|   call void asm sideeffect "", "~{r8}" ()
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|   ret void
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| }
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| 
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| ; Leaf function, frame pointer requested for non-leaf functions only, so no
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| ; need for a stack frame.
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| define void @leaf_nononleaffpelim() "frame-pointer"="non-leaf" {
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| ; CHECK-LABEL: leaf_nononleaffpelim:
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| ; CHECK-NOT: push
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| ; CHECK-NOT: sp
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| ; CHECK-NOT: pop
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| ; CHECK: bx lr
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|   ret void
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| }
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| 
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| ; Has a call, but still no need for a frame pointer.
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| define void @call() {
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| ; CHECK-LABEL: call:
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| ; CHECK: push {[[DUMMYREG:r[0-9]+]], lr}
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| ; CHECK-NOT: sp
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| ; CHECK: bl foo
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| ; CHECK: pop {[[DUMMYREG]], pc}
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|   call void @foo()
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|   ret void
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| }
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| 
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| ; Has a call, and frame pointer requested.
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| define void @call_nofpelim() "frame-pointer"="all" {
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| ; CHECK-LABEL: call_nofpelim:
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| ; CHECK: push {r7, lr}
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| ; CHECK: mov r7, sp
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| ; CHECK: bl foo
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| ; CHECK: pop {r7, pc}
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|   call void @foo()
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|   ret void
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| }
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| 
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| ; Has a call, and frame pointer requested for non-leaf function.
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| define void @call_nononleaffpelim() "frame-pointer"="non-leaf" {
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| ; CHECK-LABEL: call_nononleaffpelim:
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| ; CHECK: push {r7, lr}
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| ; CHECK: mov r7, sp
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| ; CHECK: bl foo
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| ; CHECK: pop {r7, pc}
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|   call void @foo()
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|   ret void
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| }
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| 
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| ; Has a high register clobbered, no need for a frame pointer.
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| define void @highreg() {
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| ; CHECK-LABEL: highreg:
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| ; CHECK: push.w {r8, lr}
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| ; CHECK-NOT: sp
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| ; CHECK: bl foo
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| ; CHECK: pop.w {r8, pc}
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|   call void asm sideeffect "", "~{r8}" ()
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|   call void @foo()
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|   ret void
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| }
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| 
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| ; Has a high register clobbered, frame pointer requested. We need to split the
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| ; push into two, to ensure that r7 and sp are adjacent on the stack.
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| define void @highreg_nofpelim() "frame-pointer"="all" {
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| ; CHECK-LABEL: highreg_nofpelim:
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| ; CHECK: push {[[DUMMYREG:r[0-9]+]], r7, lr}
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| ; CHECK: add r7, sp, #4
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| ; CHECK: str r8, [sp, #-4]!
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| ; CHECK: bl foo
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| ; CHECK: ldr r8, [sp], #4
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| ; CHECK: pop {[[DUMMYREG]], r7, pc}
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|   call void asm sideeffect "", "~{r8}" ()
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|   call void @foo()
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|   ret void
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| }
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| 
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| ; Has a high register clobbered, frame required due to variable-sized alloca.
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| ; We need a frame pointer to correctly restore the stack, but don't need to
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| ; split the push/pop here, because the frame pointer not required by the ABI.
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| define void @highreg_alloca(i32 %a) {
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| ; CHECK-LABEL: highreg_alloca:
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| ; CHECK: push.w {[[SOMEREGS:.*]], r7, r8, lr}
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| ; CHECK: add r7, sp, #{{[0-9]+}}
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| ; CHECK: bl foo
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| ; CHECK: pop.w {[[SOMEREGS]], r7, r8, pc}
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|   %alloca = alloca i32, i32 %a, align 4
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|   call void @foo()
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|   call void asm sideeffect "", "~{r8}" ()
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|   ret void
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| }
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| 
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| ; Has a high register clobbered, frame required due to both variable-sized
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| ; alloca and ABI. We do need to split the push/pop here.
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| define void @highreg_alloca_nofpelim(i32 %a) "frame-pointer"="all" {
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| ; CHECK-LABEL: highreg_alloca_nofpelim:
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| ; CHECK: push {[[SOMEREGS:.*]], r7, lr}
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| ; CHECK: add r7, sp, #{{[0-9]+}}
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| ; CHECK: str r8, [sp, #-4]!
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| ; CHECK: bl foo
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| ; CHECK: ldr r8, [sp], #4
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| ; CHECK: pop {[[SOMEREGS]], r7, pc}
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|   %alloca = alloca i32, i32 %a, align 4
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|   call void @foo()
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|   call void asm sideeffect "", "~{r8}" ()
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|   ret void
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| }
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