55 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			55 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: opt < %s -instcombine -S | FileCheck %s
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| 
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| target triple = "x86_64-unknown-freebsd11.0"
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| 
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| define i32 @myfls() {
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| ; CHECK-LABEL: @myfls(
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| ; CHECK-NEXT:    ret i32 6
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| ;
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|   %call = call i32 @fls(i32 42)
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|   ret i32 %call
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| }
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| 
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| define i32 @myflsl() {
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| ; CHECK-LABEL: @myflsl(
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| ; CHECK-NEXT:    ret i32 6
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| ;
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|   %patatino = call i32 @flsl(i64 42)
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|   ret i32 %patatino
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| }
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| 
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| define i32 @myflsll() {
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| ; CHECK-LABEL: @myflsll(
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| ; CHECK-NEXT:    ret i32 6
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| ;
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|   %whatever = call i32 @flsll(i64 42)
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|   ret i32 %whatever
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| }
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| 
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| ; Lower to llvm.ctlz() if the argument is not a constant
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| 
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| define i32 @flsnotconst(i64 %z) {
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| ; CHECK-LABEL: @flsnotconst(
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| ; CHECK-NEXT:    [[CTLZ:%.*]] = call i64 @llvm.ctlz.i64(i64 %z, i1 false), !range !0
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| ; CHECK-NEXT:    [[TMP1:%.*]] = trunc i64 [[CTLZ]] to i32
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| ; CHECK-NEXT:    [[TMP2:%.*]] = sub nsw i32 64, [[TMP1]]
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| ; CHECK-NEXT:    ret i32 [[TMP2]]
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| ;
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|   %goo = call i32 @flsl(i64 %z)
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|   ret i32 %goo
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| }
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| 
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| ; Make sure we lower fls(0) to 0 and not to `undef`.
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| 
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| define i32 @flszero() {
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| ; CHECK-LABEL: @flszero(
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| ; CHECK-NEXT:    ret i32 0
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| ;
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|   %zero = call i32 @fls(i32 0)
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|   ret i32 %zero
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| }
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| 
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| declare i32 @fls(i32)
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| declare i32 @flsl(i64)
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| declare i32 @flsll(i64)
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