forked from OSchip/llvm-project
36 lines
1.3 KiB
LLVM
36 lines
1.3 KiB
LLVM
; RUN: opt < %s -instcombine -S > %t
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; RUN: not grep lshr %t
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; RUN: grep add %t | count 1
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; Instcombine should be able to eliminate the lshr, because only
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; bits in the operand which might be non-zero will be shifted
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; off the end.
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define i32 @hash_string(i8* nocapture %key) nounwind readonly {
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entry:
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%t0 = load i8, i8* %key, align 1 ; <i8> [#uses=1]
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%t1 = icmp eq i8 %t0, 0 ; <i1> [#uses=1]
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br i1 %t1, label %bb2, label %bb
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bb: ; preds = %bb, %entry
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%indvar = phi i64 [ 0, %entry ], [ %tmp, %bb ] ; <i64> [#uses=2]
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%k.04 = phi i32 [ 0, %entry ], [ %t8, %bb ] ; <i32> [#uses=2]
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%cp.05 = getelementptr i8, i8* %key, i64 %indvar ; <i8*> [#uses=1]
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%t2 = shl i32 %k.04, 1 ; <i32> [#uses=1]
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%t3 = lshr i32 %k.04, 14 ; <i32> [#uses=1]
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%t4 = add i32 %t2, %t3 ; <i32> [#uses=1]
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%t5 = load i8, i8* %cp.05, align 1 ; <i8> [#uses=1]
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%t6 = sext i8 %t5 to i32 ; <i32> [#uses=1]
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%t7 = xor i32 %t6, %t4 ; <i32> [#uses=1]
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%t8 = and i32 %t7, 16383 ; <i32> [#uses=2]
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%tmp = add i64 %indvar, 1 ; <i64> [#uses=2]
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%scevgep = getelementptr i8, i8* %key, i64 %tmp ; <i8*> [#uses=1]
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%t9 = load i8, i8* %scevgep, align 1 ; <i8> [#uses=1]
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%t10 = icmp eq i8 %t9, 0 ; <i1> [#uses=1]
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br i1 %t10, label %bb2, label %bb
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bb2: ; preds = %bb, %entry
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%k.0.lcssa = phi i32 [ 0, %entry ], [ %t8, %bb ] ; <i32> [#uses=1]
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ret i32 %k.0.lcssa
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}
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