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			122 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			LLVM
		
	
	
	
	
	
			
		
		
	
	
			122 lines
		
	
	
		
			2.5 KiB
		
	
	
	
		
			LLVM
		
	
	
	
	
	
| ; RUN: opt < %s -S -early-cse | FileCheck %s
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| 
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| 
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| ; CHECK: @test1
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| define void @test1(i8 %V, i32 *%P) {
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|   %A = bitcast i64 42 to double  ;; dead
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|   %B = add i32 4, 19             ;; constant folds
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|   store i32 %B, i32* %P
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|   ; CHECK-NEXT: store i32 23, i32* %P
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|   
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|   %C = zext i8 %V to i32
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|   %D = zext i8 %V to i32  ;; CSE
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|   store volatile i32 %C, i32* %P
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|   store volatile i32 %D, i32* %P
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|   ; CHECK-NEXT: %C = zext i8 %V to i32
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|   ; CHECK-NEXT: store volatile i32 %C
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|   ; CHECK-NEXT: store volatile i32 %C
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|   
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|   %E = add i32 %C, %C
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|   %F = add i32 %C, %C
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|   store volatile i32 %E, i32* %P
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|   store volatile i32 %F, i32* %P
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|   ; CHECK-NEXT: %E = add i32 %C, %C
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|   ; CHECK-NEXT: store volatile i32 %E
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|   ; CHECK-NEXT: store volatile i32 %E
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| 
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|   %G = add nuw i32 %C, %C         ;; not a CSE with E
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|   store volatile i32 %G, i32* %P
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|   ; CHECK-NEXT: %G = add nuw i32 %C, %C
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|   ; CHECK-NEXT: store volatile i32 %G
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|   ret void
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| }
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| 
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| 
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| ;; Simple load value numbering.
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| ; CHECK: @test2
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| define i32 @test2(i32 *%P) {
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|   %V1 = load i32* %P
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|   %V2 = load i32* %P
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|   %Diff = sub i32 %V1, %V2
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|   ret i32 %Diff
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|   ; CHECK: ret i32 0
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| }
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| 
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| ;; Cross block load value numbering.
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| ; CHECK: @test3
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| define i32 @test3(i32 *%P, i1 %Cond) {
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|   %V1 = load i32* %P
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|   br i1 %Cond, label %T, label %F
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| T:
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|   store i32 4, i32* %P
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|   ret i32 42
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| F:
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|   %V2 = load i32* %P
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|   %Diff = sub i32 %V1, %V2
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|   ret i32 %Diff
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|   ; CHECK: F:
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|   ; CHECK: ret i32 0
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| }
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| 
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| ;; Cross block load value numbering stops when stores happen.
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| ; CHECK: @test4
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| define i32 @test4(i32 *%P, i1 %Cond) {
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|   %V1 = load i32* %P
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|   br i1 %Cond, label %T, label %F
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| T:
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|   ret i32 42
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| F:
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|   ; Clobbers V1
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|   store i32 42, i32* %P
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|   
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|   %V2 = load i32* %P
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|   %Diff = sub i32 %V1, %V2
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|   ret i32 %Diff
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|   ; CHECK: F:
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|   ; CHECK: ret i32 %Diff
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| }
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| 
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| declare i32 @func(i32 *%P) readonly
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| 
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| ;; Simple call CSE'ing.
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| ; CHECK: @test5
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| define i32 @test5(i32 *%P) {
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|   %V1 = call i32 @func(i32* %P)
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|   %V2 = call i32 @func(i32* %P)
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|   %Diff = sub i32 %V1, %V2
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|   ret i32 %Diff
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|   ; CHECK: ret i32 0
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| }
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| 
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| ;; Trivial Store->load forwarding
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| ; CHECK: @test6
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| define i32 @test6(i32 *%P) {
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|   store i32 42, i32* %P
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|   %V1 = load i32* %P
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|   ret i32 %V1
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|   ; CHECK: ret i32 42
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| }
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| 
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| ;; Trivial dead store elimination.
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| ; CHECK: @test7
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| define void @test7(i32 *%P) {
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|   store i32 42, i32* %P
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|   store i32 45, i32* %P
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|   ret void
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|   ; CHECK-NEXT: store i32 45
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|   ; CHECK-NEXT: ret void
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| }
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| 
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| ;; Readnone functions aren't invalidated by stores.
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| ; CHECK: @test8
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| define i32 @test8(i32 *%P) {
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|   %V1 = call i32 @func(i32* %P) readnone
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|   store i32 4, i32* %P
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|   %V2 = call i32 @func(i32* %P) readnone
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|   %Diff = sub i32 %V1, %V2
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|   ret i32 %Diff
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|   ; CHECK: ret i32 0
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| }
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| 
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| 
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