85 lines
2.4 KiB
LLVM
85 lines
2.4 KiB
LLVM
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; RUN: opt -phi-values -gvn -S < %s | FileCheck %s
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declare noalias i8* @malloc(i64)
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; Detecting that %s is fully redundant should let us detect that %w is partially
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; redundant.
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define void @fn1(i32** noalias %start, i32* %width, i32 %h) {
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; CHECK-LABEL: @fn1
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entry:
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%call = tail call noalias i8* @malloc(i64 1024)
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%call.cast = bitcast i8* %call to i32*
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store i32* %call.cast, i32** %start, align 8
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br label %preheader
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preheader:
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%cmp = icmp slt i32 1, %h
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br i1 %cmp, label %body, label %exit
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; CHECK-LABEL: preheader.body_crit_edge:
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; CHECK: load i32, i32* %width, align 8
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; CHECK-LABEL: body:
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; CHECK-NOT: load i32*, i32** %start, align 8
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; CHECK-NOT: load i32, i32* %width, align 8
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body:
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%j = phi i32 [ 0, %preheader ], [ %j.next, %body ]
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%s = load i32*, i32** %start, align 8
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%idx = getelementptr inbounds i32, i32* %s, i64 0
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store i32 0, i32* %idx, align 4
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%j.next = add nuw nsw i32 %j, 1
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%w = load i32, i32* %width, align 8
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%cmp3 = icmp slt i32 %j.next, %w
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br i1 %cmp3, label %body, label %preheader
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exit:
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ret void
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}
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; %s is fully redundant but has more than one available value. Detecting that
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; %w is partially redundant requires alias analysis that can analyze those
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; values.
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define void @fn2(i32** noalias %start, i32* %width, i32 %h, i32 %arg) {
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; CHECK-LABEL: @fn2
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entry:
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%call = tail call noalias i8* @malloc(i64 1024)
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%call.cast = bitcast i8* %call to i32*
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%cmp1 = icmp slt i32 %arg, 0
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br i1 %cmp1, label %if, label %else
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if:
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store i32* %call.cast, i32** %start, align 8
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br label %preheader
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else:
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%gep = getelementptr inbounds i32, i32* %call.cast, i32 %arg
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store i32* %gep, i32** %start, align 8
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br label %preheader
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; CHECK-LABEL: preheader:
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; CHECK: %s = phi i32* [ %s, %body ], [ %gep, %else ], [ %call.cast, %if ]
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preheader:
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%cmp = icmp slt i32 1, %h
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br i1 %cmp, label %body, label %exit
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; CHECK-LABEL: preheader.body_crit_edge:
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; CHECK: load i32, i32* %width, align 8
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; CHECK-LABEL: body:
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; CHECK-NOT: load i32*, i32** %start, align 8
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; CHECK-NOT: load i32, i32* %width, align 8
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body:
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%j = phi i32 [ 0, %preheader ], [ %j.next, %body ]
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%s = load i32*, i32** %start, align 8
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%idx = getelementptr inbounds i32, i32* %s, i64 0
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store i32 0, i32* %idx, align 4
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%j.next = add nuw nsw i32 %j, 1
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%w = load i32, i32* %width, align 8
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%cmp3 = icmp slt i32 %j.next, %w
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br i1 %cmp3, label %body, label %preheader
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exit:
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ret void
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}
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