forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			78 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			78 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; RUN: llc < %s -march=x86 | FileCheck %s
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| 
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| define i32 @t1(i8* %X, i32 %i) {
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| ; CHECK-LABEL: t1:
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| ; CHECK-NOT: and
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| ; CHECK: movzbl
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| ; CHECK: movl (%{{...}},%{{...}},4),
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| ; CHECK: ret
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| 
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| entry:
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|   %tmp2 = shl i32 %i, 2
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|   %tmp4 = and i32 %tmp2, 1020
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|   %tmp7 = getelementptr i8* %X, i32 %tmp4
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|   %tmp78 = bitcast i8* %tmp7 to i32*
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|   %tmp9 = load i32* %tmp78
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|   ret i32 %tmp9
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| }
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| 
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| define i32 @t2(i16* %X, i32 %i) {
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| ; CHECK-LABEL: t2:
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| ; CHECK-NOT: and
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| ; CHECK: movzwl
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| ; CHECK: movl (%{{...}},%{{...}},4),
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| ; CHECK: ret
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| 
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| entry:
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|   %tmp2 = shl i32 %i, 1
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|   %tmp4 = and i32 %tmp2, 131070
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|   %tmp7 = getelementptr i16* %X, i32 %tmp4
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|   %tmp78 = bitcast i16* %tmp7 to i32*
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|   %tmp9 = load i32* %tmp78
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|   ret i32 %tmp9
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| }
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| 
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| define i32 @t3(i16* %i.ptr, i32* %arr) {
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| ; This case is tricky. The lshr followed by a gep will produce a lshr followed
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| ; by an and to remove the low bits. This can be simplified by doing the lshr by
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| ; a greater constant and using the addressing mode to scale the result back up.
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| ; To make matters worse, because of the two-phase zext of %i and their reuse in
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| ; the function, the DAG can get confusing trying to re-use both of them and
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| ; prevent easy analysis of the mask in order to match this.
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| ; CHECK-LABEL: t3:
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| ; CHECK-NOT: and
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| ; CHECK: shrl
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| ; CHECK: addl (%{{...}},%{{...}},4),
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| ; CHECK: ret
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| 
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| entry:
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|   %i = load i16* %i.ptr
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|   %i.zext = zext i16 %i to i32
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|   %index = lshr i32 %i.zext, 11
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|   %val.ptr = getelementptr inbounds i32* %arr, i32 %index
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|   %val = load i32* %val.ptr
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|   %sum = add i32 %val, %i.zext
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|   ret i32 %sum
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| }
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| 
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| define i32 @t4(i16* %i.ptr, i32* %arr) {
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| ; A version of @t3 that has more zero extends and more re-use of intermediate
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| ; values. This exercise slightly different bits of canonicalization.
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| ; CHECK-LABEL: t4:
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| ; CHECK-NOT: and
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| ; CHECK: shrl
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| ; CHECK: addl (%{{...}},%{{...}},4),
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| ; CHECK: ret
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| 
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| entry:
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|   %i = load i16* %i.ptr
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|   %i.zext = zext i16 %i to i32
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|   %index = lshr i32 %i.zext, 11
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|   %index.zext = zext i32 %index to i64
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|   %val.ptr = getelementptr inbounds i32* %arr, i64 %index.zext
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|   %val = load i32* %val.ptr
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|   %sum.1 = add i32 %val, %i.zext
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|   %sum.2 = add i32 %sum.1, %index
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|   ret i32 %sum.2
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| }
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