96 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			96 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; Test shrink wrapping placement is correct with respect to calls to llvm.{stacksave,stackrestore}
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| 
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| ; void f(int n, int x[]) {
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| ;   if (n < 0)
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| ;     return;
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| ;
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| ;  int a[n];
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| ;
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| ;  for (int i = 0; i < n; i++)
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| ;    a[i] = x[n - i - 1];
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| ;
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| ;  for (int i = 0; i < n; i++)
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| ;    x[i] = a[i] + 1;
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| ; }
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| ;
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| ; RUN: llc -mtriple aarch64-linux %s -o - | FileCheck %s
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| 
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| define dso_local void @f(i32 %n, i32* nocapture %x) {
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| entry:
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|   %cmp = icmp slt i32 %n, 0
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|   br i1 %cmp, label %return, label %if.end
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| 
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| if.end:                                           ; preds = %entry
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|   %0 = zext i32 %n to i64
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|   %1 = tail call i8* @llvm.stacksave()
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|   %vla = alloca i32, i64 %0, align 16
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|   %cmp132 = icmp eq i32 %n, 0
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|   br i1 %cmp132, label %for.cond.cleanup8, label %for.body.lr.ph
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| 
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| for.body.lr.ph:                                   ; preds = %if.end
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|   %sub = add i32 %n, -1
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|   br label %for.body
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| 
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| for.cond6.preheader:                              ; preds = %for.body
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|   %cmp730 = icmp sgt i32 %n, 0
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|   br i1 %cmp730, label %for.body9, label %for.cond.cleanup8
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| 
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| for.body:                                         ; preds = %for.body, %for.body.lr.ph
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|   %indvars.iv34 = phi i64 [ 0, %for.body.lr.ph ], [ %indvars.iv.next35, %for.body ]
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|   %2 = trunc i64 %indvars.iv34 to i32
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|   %sub2 = sub i32 %sub, %2
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|   %idxprom = sext i32 %sub2 to i64
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|   %arrayidx = getelementptr inbounds i32, i32* %x, i64 %idxprom
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|   %3 = load i32, i32* %arrayidx, align 4
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|   %arrayidx4 = getelementptr inbounds i32, i32* %vla, i64 %indvars.iv34
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|   store i32 %3, i32* %arrayidx4, align 4
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|   %indvars.iv.next35 = add nuw nsw i64 %indvars.iv34, 1
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|   %exitcond37 = icmp eq i64 %indvars.iv.next35, %0
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|   br i1 %exitcond37, label %for.cond6.preheader, label %for.body
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| 
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| for.cond.cleanup8:                                ; preds = %for.body9, %if.end, %for.cond6.preheader
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|   tail call void @llvm.stackrestore(i8* %1)
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|   br label %return
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| 
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| for.body9:                                        ; preds = %for.cond6.preheader, %for.body9
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|   %indvars.iv = phi i64 [ %indvars.iv.next, %for.body9 ], [ 0, %for.cond6.preheader ]
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|   %arrayidx11 = getelementptr inbounds i32, i32* %vla, i64 %indvars.iv
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|   %4 = load i32, i32* %arrayidx11, align 4
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|   %add = add nsw i32 %4, 1
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|   %arrayidx13 = getelementptr inbounds i32, i32* %x, i64 %indvars.iv
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|   store i32 %add, i32* %arrayidx13, align 4
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|   %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
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|   %exitcond = icmp eq i64 %indvars.iv.next, %0
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|   br i1 %exitcond, label %for.cond.cleanup8, label %for.body9
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| 
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| return:                                           ; preds = %entry, %for.cond.cleanup8
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|   ret void
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| }
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| 
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| ; Function Attrs: nounwind
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| declare i8* @llvm.stacksave()
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| 
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| ; Function Attrs: nounwind
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| declare void @llvm.stackrestore(i8*)
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| 
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| ; Check that llvm.stackrestore() happens before CSRs are popped off the stack
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| 
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| ; CHECK-LABEL: f
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| 
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| ; CHECK:      stp x29, x30, [sp, #-16]!
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| ; CHECK-NEXT: mov x29, sp
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| 
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| ; VLA allocation
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| ; CHECK: add [[X1:x[0-9]+]], [[X1]], #15
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| ; CHECK: mov [[X2:x[0-9]+]], sp
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| ; CHECK: and [[X1]], [[X1]], #0x7fffffff0
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| ; Saving the SP via llvm.stacksave()
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| ; CHECK: mov [[SAVE:x[0-9]+]], sp
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| ; CHECK: sub [[X2]], [[X2]], [[X1]]
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| 
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| ; The next instruction comes from llvm.stackrestore()
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| ; CHECK:      mov sp, [[SAVE]]
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| ; Epilogue
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| ; CHECK-NEXT: mov sp, x29
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| ; CHECK-NEXT: ldp x29, x30, [sp], #16
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