1 ; RUN: opt < %s -instcombine -S > %t 2 ; RUN: not grep lshr %t 3 ; RUN: grep add %t | count 1 4 5 ; Instcombine should be able to eliminate the lshr, because only 6 ; bits in the operand which might be non-zero will be shifted 7 ; off the end. 8 9 define i32 @hash_string(i8* nocapture %key) nounwind readonly { 10 entry: 11 %t0 = load i8* %key, align 1 ; <i8> [#uses=1] 12 %t1 = icmp eq i8 %t0, 0 ; <i1> [#uses=1] 13 br i1 %t1, label %bb2, label %bb 14 15 bb: ; preds = %bb, %entry 16 %indvar = phi i64 [ 0, %entry ], [ %tmp, %bb ] ; <i64> [#uses=2] 17 %k.04 = phi i32 [ 0, %entry ], [ %t8, %bb ] ; <i32> [#uses=2] 18 %cp.05 = getelementptr i8* %key, i64 %indvar ; <i8*> [#uses=1] 19 %t2 = shl i32 %k.04, 1 ; <i32> [#uses=1] 20 %t3 = lshr i32 %k.04, 14 ; <i32> [#uses=1] 21 %t4 = add i32 %t2, %t3 ; <i32> [#uses=1] 22 %t5 = load i8* %cp.05, align 1 ; <i8> [#uses=1] 23 %t6 = sext i8 %t5 to i32 ; <i32> [#uses=1] 24 %t7 = xor i32 %t6, %t4 ; <i32> [#uses=1] 25 %t8 = and i32 %t7, 16383 ; <i32> [#uses=2] 26 %tmp = add i64 %indvar, 1 ; <i64> [#uses=2] 27 %scevgep = getelementptr i8* %key, i64 %tmp ; <i8*> [#uses=1] 28 %t9 = load i8* %scevgep, align 1 ; <i8> [#uses=1] 29 %t10 = icmp eq i8 %t9, 0 ; <i1> [#uses=1] 30 br i1 %t10, label %bb2, label %bb 31 32 bb2: ; preds = %bb, %entry 33 %k.0.lcssa = phi i32 [ 0, %entry ], [ %t8, %bb ] ; <i32> [#uses=1] 34 ret i32 %k.0.lcssa 35 } 36
