78 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt %s -simplifycfg -S | FileCheck %s
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| 
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| declare i32 @f(i32)
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| 
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| define i32 @basic(i32 %x) {
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| ; CHECK-LABEL: @basic
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| ; CHECK: x.off = add i32 %x, -5
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| ; CHECK: %switch = icmp ult i32 %x.off, 3
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| ; CHECK: br i1 %switch, label %a, label %default
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| 
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| entry:
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|   switch i32 %x, label %default [
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|     i32 5, label %a
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|     i32 6, label %a
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|     i32 7, label %a
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|   ]
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| default:
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|   %0 = call i32 @f(i32 0)
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|   ret i32 %0
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| a:
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|   %1 = call i32 @f(i32 1)
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|   ret i32 %1
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| }
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| 
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| 
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| define i32 @unreachable(i32 %x) {
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| ; CHECK-LABEL: @unreachable
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| ; CHECK: x.off = add i32 %x, -5
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| ; CHECK: %switch = icmp ult i32 %x.off, 3
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| ; CHECK: br i1 %switch, label %a, label %b
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| 
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| entry:
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|   switch i32 %x, label %unreachable [
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|     i32 5, label %a
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|     i32 6, label %a
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|     i32 7, label %a
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|     i32 10, label %b
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|     i32 20, label %b
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|     i32 30, label %b
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|     i32 40, label %b
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|   ]
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| unreachable:
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|   unreachable
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| a:
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|   %0 = call i32 @f(i32 0)
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|   ret i32 %0
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| b:
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|   %1 = call i32 @f(i32 1)
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|   ret i32 %1
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| }
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| 
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| 
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| define i32 @unreachable2(i32 %x) {
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| ; CHECK-LABEL: @unreachable2
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| ; CHECK: x.off = add i32 %x, -5
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| ; CHECK: %switch = icmp ult i32 %x.off, 3
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| ; CHECK: br i1 %switch, label %a, label %b
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| 
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| entry:
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|   ; Note: folding the most popular case destination into the default
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|   ; would prevent switch-to-icmp here.
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|   switch i32 %x, label %unreachable [
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|     i32 5, label %a
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|     i32 6, label %a
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|     i32 7, label %a
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|     i32 10, label %b
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|     i32 20, label %b
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|   ]
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| unreachable:
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|   unreachable
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| a:
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|   %0 = call i32 @f(i32 0)
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|   ret i32 %0
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| b:
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|   %1 = call i32 @f(i32 1)
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|   ret i32 %1
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| }
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