119 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			119 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: opt -S -gvn -enable-load-pre < %s | FileCheck %s
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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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target triple = "x86_64-unknown-linux-gnu"
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; These tests exercise situations when instructions that were first instructions
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; with implicit control flow get removed. We make sure that after that we don't
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; face crashes and are still able to perform PRE correctly.
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declare i32 @foo(i32 %arg) #0
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define hidden void @test_01(i32 %x, i32 %y) {
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; c2 only throws if c1 throws, so it can be safely removed and then PRE can
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; hoist the load out of loop.
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; CHECK-LABEL: @test_01
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; CHECK:       entry:
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; CHECK-NEXT:    %c1 = call i32 @foo(i32 %x)
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; CHECK-NEXT:    %val.pre = load i32, i32* null, align 8
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; CHECK-NEXT:    br label %loop
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; CHECK:       loop:
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; CHECK-NEXT:    %c3 = call i32 @foo(i32 %val.pre)
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; CHECK-NEXT:    br label %loop
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entry:
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  %c1 = call i32 @foo(i32 %x)
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  br label %loop
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loop:
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  %c2 = call i32 @foo(i32 %x)
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  %val = load i32, i32* null, align 8
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  %c3 = call i32 @foo(i32 %val)
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  br label %loop
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}
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define hidden void @test_02(i32 %x, i32 %y) {
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; PRE is not allowed because c2 may throw.
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; CHECK-LABEL: @test_02
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; CHECK:       entry:
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; CHECK-NEXT:    %c1 = call i32 @foo(i32 %x)
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; CHECK-NEXT:    br label %loop
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; CHECK:       loop:
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; CHECK-NEXT:    %c2 = call i32 @foo(i32 %y)
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; CHECK-NEXT:    %val = load i32, i32* null, align 8
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; CHECK-NEXT:    %c3 = call i32 @foo(i32 %val)
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; CHECK-NEXT:    br label %loop
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entry:
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  %c1 = call i32 @foo(i32 %x)
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  br label %loop
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loop:
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  %c2 = call i32 @foo(i32 %y)
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  %val = load i32, i32* null, align 8
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  %c3 = call i32 @foo(i32 %val)
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  br label %loop
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}
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define hidden void @test_03(i32 %x, i32 %y) {
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; PRE of load is allowed because c2 only throws if c1 throws. c3 should
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; not be eliminated. c4 is eliminated because it only throws if c3 throws.
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; CHECK-LABEL: @test_03
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; CHECK:       entry:
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; CHECK-NEXT:    %c1 = call i32 @foo(i32 %x)
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; CHECK-NEXT:    %val.pre = load i32, i32* null, align 8
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; CHECK-NEXT:    br label %loop
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; CHECK:       loop:
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; CHECK-NEXT:    %c3 = call i32 @foo(i32 %y)
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; CHECK-NEXT:    %c5 = call i32 @foo(i32 %val.pre)
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; CHECK-NEXT:    br label %loop
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entry:
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  %c1 = call i32 @foo(i32 %x)
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  br label %loop
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loop:
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  %c2 = call i32 @foo(i32 %x)
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  %val = load i32, i32* null, align 8
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  %c3 = call i32 @foo(i32 %y)
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  %val2 = load i32, i32* null, align 8
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  %c4 = call i32 @foo(i32 %y)
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  %c5 = call i32 @foo(i32 %val)
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  br label %loop
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}
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define hidden void @test_04(i32 %x, i32 %y) {
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; PRE is not allowed even after we remove c2 because now c3 prevents us from it.
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; CHECK-LABEL: @test_04
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; CHECK:       entry:
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; CHECK-NEXT:    %c1 = call i32 @foo(i32 %x)
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; CHECK-NEXT:    br label %loop
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; CHECK:       loop:
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; CHECK-NEXT:    %c3 = call i32 @foo(i32 %y)
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; CHECK-NEXT:    %val = load i32, i32* null, align 8
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; CHECK-NEXT:    %c5 = call i32 @foo(i32 %val)
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; CHECK-NEXT:    br label %loop
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entry:
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  %c1 = call i32 @foo(i32 %x)
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  br label %loop
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loop:
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  %c2 = call i32 @foo(i32 %x)
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  %c3 = call i32 @foo(i32 %y)
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  %val = load i32, i32* null, align 8
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  %c4 = call i32 @foo(i32 %y)
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  %c5 = call i32 @foo(i32 %val)
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  br label %loop
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}
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attributes #0 = { readnone }
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