1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py 2; RUN: opt < %s -instcombine -S | FileCheck %s 3 4; Instcombine should be able to eliminate the lshr, because only 5; bits in the operand which might be non-zero will be shifted 6; off the end. 7 8define i32 @hash_string(i8* nocapture %key) nounwind readonly { 9; CHECK-LABEL: @hash_string( 10; CHECK-NEXT: entry: 11; CHECK-NEXT: [[T0:%.*]] = load i8, i8* [[KEY:%.*]], align 1 12; CHECK-NEXT: [[T1:%.*]] = icmp eq i8 [[T0]], 0 13; CHECK-NEXT: br i1 [[T1]], label [[BB2:%.*]], label [[BB:%.*]] 14; CHECK: bb: 15; CHECK-NEXT: [[INDVAR:%.*]] = phi i64 [ 0, [[ENTRY:%.*]] ], [ [[T:%.*]], [[BB]] ] 16; CHECK-NEXT: [[K_04:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[T8:%.*]], [[BB]] ] 17; CHECK-NEXT: [[CP_05:%.*]] = getelementptr i8, i8* [[KEY]], i64 [[INDVAR]] 18; CHECK-NEXT: [[T2:%.*]] = shl nuw nsw i32 [[K_04]], 1 19; CHECK-NEXT: [[T5:%.*]] = load i8, i8* [[CP_05]], align 1 20; CHECK-NEXT: [[T6:%.*]] = sext i8 [[T5]] to i32 21; CHECK-NEXT: [[T7:%.*]] = xor i32 [[T2]], [[T6]] 22; CHECK-NEXT: [[T8]] = and i32 [[T7]], 16383 23; CHECK-NEXT: [[T]] = add i64 [[INDVAR]], 1 24; CHECK-NEXT: [[SCEVGEP:%.*]] = getelementptr i8, i8* [[KEY]], i64 [[T]] 25; CHECK-NEXT: [[T9:%.*]] = load i8, i8* [[SCEVGEP]], align 1 26; CHECK-NEXT: [[T10:%.*]] = icmp eq i8 [[T9]], 0 27; CHECK-NEXT: br i1 [[T10]], label [[BB2]], label [[BB]] 28; CHECK: bb2: 29; CHECK-NEXT: [[K_0_LCSSA:%.*]] = phi i32 [ 0, [[ENTRY]] ], [ [[T8]], [[BB]] ] 30; CHECK-NEXT: ret i32 [[K_0_LCSSA]] 31; 32entry: 33 %t0 = load i8, i8* %key, align 1 34 %t1 = icmp eq i8 %t0, 0 35 br i1 %t1, label %bb2, label %bb 36 37bb: 38 %indvar = phi i64 [ 0, %entry ], [ %t, %bb ] 39 %k.04 = phi i32 [ 0, %entry ], [ %t8, %bb ] 40 %cp.05 = getelementptr i8, i8* %key, i64 %indvar 41 %t2 = shl i32 %k.04, 1 42 %t3 = lshr i32 %k.04, 14 43 %t4 = add i32 %t2, %t3 44 %t5 = load i8, i8* %cp.05, align 1 45 %t6 = sext i8 %t5 to i32 46 %t7 = xor i32 %t6, %t4 47 %t8 = and i32 %t7, 16383 48 %t = add i64 %indvar, 1 49 %scevgep = getelementptr i8, i8* %key, i64 %t 50 %t9 = load i8, i8* %scevgep, align 1 51 %t10 = icmp eq i8 %t9, 0 52 br i1 %t10, label %bb2, label %bb 53 54bb2: 55 %k.0.lcssa = phi i32 [ 0, %entry ], [ %t8, %bb ] 56 ret i32 %k.0.lcssa 57} 58