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132f4f81f0
Given below case: %y = shl %x, n %z = ashr %y, m when n = m, SCEV models it as sext(trunc(x)). This patch tries to handle the case where n > m by using sext(mul(trunc(x), 2^(n-m)))) as the SCEV expression. llvm-svn: 298631
40 lines
1.4 KiB
LLVM
40 lines
1.4 KiB
LLVM
; RUN: opt < %s -analyze -scalar-evolution | FileCheck %s
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; CHECK: %tmp9 = shl i64 %tmp8, 33
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; CHECK-NEXT: --> {{.*}} Exits: (-8589934592 + (8589934592 * (zext i32 %arg2 to i64)))
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; CHECK-NEXT: %tmp10 = ashr exact i64 %tmp9, 0
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; CHECK-NEXT: --> {{.*}} Exits: (-8589934592 + (8589934592 * (zext i32 %arg2 to i64)))
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define void @foo(i32* nocapture %arg, i32 %arg1, i32 %arg2) {
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bb:
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%tmp = icmp sgt i32 %arg2, 0
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br i1 %tmp, label %bb3, label %bb6
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bb3: ; preds = %bb
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%tmp4 = zext i32 %arg2 to i64
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br label %bb7
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bb5: ; preds = %bb7
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br label %bb6
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bb6: ; preds = %bb5, %bb
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ret void
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bb7: ; preds = %bb7, %bb3
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%tmp8 = phi i64 [ %tmp18, %bb7 ], [ 0, %bb3 ]
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%tmp9 = shl i64 %tmp8, 33
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%tmp10 = ashr exact i64 %tmp9, 0
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%tmp11 = getelementptr inbounds i32, i32* %arg, i64 %tmp10
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%tmp12 = load i32, i32* %tmp11, align 4
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%tmp13 = sub nsw i32 %tmp12, %arg1
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store i32 %tmp13, i32* %tmp11, align 4
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%tmp14 = or i64 %tmp10, 1
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%tmp15 = getelementptr inbounds i32, i32* %arg, i64 %tmp14
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%tmp16 = load i32, i32* %tmp15, align 4
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%tmp17 = mul nsw i32 %tmp16, %arg1
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store i32 %tmp17, i32* %tmp15, align 4
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%tmp18 = add nuw nsw i64 %tmp8, 1
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%tmp19 = icmp eq i64 %tmp18, %tmp4
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br i1 %tmp19, label %bb5, label %bb7
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}
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