; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=instcombine -S | FileCheck %s ; std::bit_ceil(x) define i32 @bit_ceil_32(i32 %x) { ; CHECK-LABEL: @bit_ceil_32( ; CHECK-NEXT: [[DEC:%.*]] = add i32 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[DEC]], i1 false), !range [[RNG0:![0-9]+]] ; CHECK-NEXT: [[TMP1:%.*]] = sub nsw i32 0, [[CTLZ]] ; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP1]], 31 ; CHECK-NEXT: [[SEL:%.*]] = shl nuw i32 1, [[TMP2]] ; CHECK-NEXT: ret i32 [[SEL]] ; %dec = add i32 %x, -1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %dec, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %ugt = icmp ugt i32 %x, 1 %sel = select i1 %ugt, i32 %shl, i32 1 ret i32 %sel } ; std::bit_ceil(x) define i64 @bit_ceil_64(i64 %x) { ; CHECK-LABEL: @bit_ceil_64( ; CHECK-NEXT: [[DEC:%.*]] = add i64 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i64 @llvm.ctlz.i64(i64 [[DEC]], i1 false), !range [[RNG1:![0-9]+]] ; CHECK-NEXT: [[TMP1:%.*]] = sub nsw i64 0, [[CTLZ]] ; CHECK-NEXT: [[TMP2:%.*]] = and i64 [[TMP1]], 63 ; CHECK-NEXT: [[SEL:%.*]] = shl nuw i64 1, [[TMP2]] ; CHECK-NEXT: ret i64 [[SEL]] ; %dec = add i64 %x, -1 %ctlz = tail call i64 @llvm.ctlz.i64(i64 %dec, i1 false) %sub = sub i64 64, %ctlz %shl = shl i64 1, %sub %ugt = icmp ugt i64 %x, 1 %sel = select i1 %ugt, i64 %shl, i64 1 ret i64 %sel } ; std::bit_ceil(x - 1) define i32 @bit_ceil_32_minus_1(i32 %x) { ; CHECK-LABEL: @bit_ceil_32_minus_1( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[SUB:%.*]] = add i32 [[X:%.*]], -2 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[SUB]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[TMP0:%.*]] = sub nsw i32 0, [[CTLZ]] ; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[TMP0]], 31 ; CHECK-NEXT: [[SEL:%.*]] = shl nuw i32 1, [[TMP1]] ; CHECK-NEXT: ret i32 [[SEL]] ; entry: %sub = add i32 %x, -2 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %sub, i1 false) %sub2 = sub nuw nsw i32 32, %ctlz %shl = shl nuw i32 1, %sub2 %add = add i32 %x, -3 %ult = icmp ult i32 %add, -2 %sel = select i1 %ult, i32 %shl, i32 1 ret i32 %sel } ; std::bit_ceil(x + 1) define i32 @bit_ceil_32_plus_1(i32 %x) { ; CHECK-LABEL: @bit_ceil_32_plus_1( ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[TMP1:%.*]] = sub nsw i32 0, [[CTLZ]] ; CHECK-NEXT: [[TMP2:%.*]] = and i32 [[TMP1]], 31 ; CHECK-NEXT: [[SEL:%.*]] = shl nuw i32 1, [[TMP2]] ; CHECK-NEXT: ret i32 [[SEL]] ; %ctlz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %dec = add i32 %x, -1 %ult = icmp ult i32 %dec, -2 %sel = select i1 %ult, i32 %shl, i32 1 ret i32 %sel } ; std::bit_ceil(x + 2) define i32 @bit_ceil_plus_2(i32 %x) { ; CHECK-LABEL: @bit_ceil_plus_2( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[SUB:%.*]] = add i32 [[X:%.*]], 1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[SUB]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[TMP0:%.*]] = sub nsw i32 0, [[CTLZ]] ; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[TMP0]], 31 ; CHECK-NEXT: [[SEL:%.*]] = shl nuw i32 1, [[TMP1]] ; CHECK-NEXT: ret i32 [[SEL]] ; entry: %sub = add i32 %x, 1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %sub, i1 false) %sub2 = sub nuw nsw i32 32, %ctlz %shl = shl nuw i32 1, %sub2 %ult = icmp ult i32 %x, -2 %sel = select i1 %ult, i32 %shl, i32 1 ret i32 %sel } ; std::bit_ceil(-x) define i32 @bit_ceil_32_neg(i32 %x) { ; CHECK-LABEL: @bit_ceil_32_neg( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[SUB:%.*]] = xor i32 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[SUB]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[TMP0:%.*]] = sub nsw i32 0, [[CTLZ]] ; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[TMP0]], 31 ; CHECK-NEXT: [[SEL:%.*]] = shl nuw i32 1, [[TMP1]] ; CHECK-NEXT: ret i32 [[SEL]] ; entry: %sub = xor i32 %x, -1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %sub, i1 false) %sub2 = sub nuw nsw i32 32, %ctlz %shl = shl nuw i32 1, %sub2 %notsub = add i32 %x, -1 %ult = icmp ult i32 %notsub, -2 %sel = select i1 %ult, i32 %shl, i32 1 ret i32 %sel } ; std::bit_ceil(~x) define i32 @bit_ceil_not(i32 %x) { ; CHECK-LABEL: @bit_ceil_not( ; CHECK-NEXT: entry: ; CHECK-NEXT: [[SUB:%.*]] = sub i32 -2, [[X:%.*]] ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[SUB]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[TMP0:%.*]] = sub nsw i32 0, [[CTLZ]] ; CHECK-NEXT: [[TMP1:%.*]] = and i32 [[TMP0]], 31 ; CHECK-NEXT: [[SEL:%.*]] = shl nuw i32 1, [[TMP1]] ; CHECK-NEXT: ret i32 [[SEL]] ; entry: %sub = sub i32 -2, %x %ctlz = tail call i32 @llvm.ctlz.i32(i32 %sub, i1 false) %sub2 = sub nuw nsw i32 32, %ctlz %shl = shl nuw i32 1, %sub2 %ult = icmp ult i32 %x, -2 %sel = select i1 %ult, i32 %shl, i32 1 ret i32 %sel } ; Commuted select operands should still be recognized. define i32 @bit_ceil_commuted_operands(i32 %x) { ; CHECK-LABEL: @bit_ceil_commuted_operands( ; CHECK-NEXT: [[DEC:%.*]] = add i32 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[DEC]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: ret i32 [[SHL]] ; %dec = add i32 %x, -1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %dec, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %eq = icmp eq i32 %dec, 0 %sel = select i1 %eq, i32 1, i32 %shl ret i32 %sel } ; Negative test: wrong select constant define i32 @bit_ceil_wrong_select_constant(i32 %x) { ; CHECK-LABEL: @bit_ceil_wrong_select_constant( ; CHECK-NEXT: [[DEC:%.*]] = add i32 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[DEC]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[UGT_INV:%.*]] = icmp ult i32 [[X]], 2 ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[UGT_INV]], i32 2, i32 [[SHL]] ; CHECK-NEXT: ret i32 [[SEL]] ; %dec = add i32 %x, -1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %dec, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %ugt = icmp ugt i32 %x, 1 %sel = select i1 %ugt, i32 %shl, i32 2 ret i32 %sel } ; Negative test: select condition != false does not guarantee ctlz being either 0 or 32 define i32 @bit_ceil_32_wrong_cond(i32 %x) { ; CHECK-LABEL: @bit_ceil_32_wrong_cond( ; CHECK-NEXT: [[DEC:%.*]] = add i32 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[DEC]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[UGT:%.*]] = icmp ugt i32 [[X]], 2 ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[UGT]], i32 [[SHL]], i32 1 ; CHECK-NEXT: ret i32 [[SEL]] ; %dec = add i32 %x, -1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %dec, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %ugt = icmp ugt i32 %x, 2 %sel = select i1 %ugt, i32 %shl, i32 1 ret i32 %sel } ; Negative test: wrong sub constant define i32 @bit_ceil_wrong_sub_constant(i32 %x) { ; CHECK-LABEL: @bit_ceil_wrong_sub_constant( ; CHECK-NEXT: [[DEC:%.*]] = add i32 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[DEC]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 33, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[UGT:%.*]] = icmp ugt i32 [[X]], 1 ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[UGT]], i32 [[SHL]], i32 1 ; CHECK-NEXT: ret i32 [[SEL]] ; %dec = add i32 %x, -1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %dec, i1 false) %sub = sub i32 33, %ctlz %shl = shl i32 1, %sub %ugt = icmp ugt i32 %x, 1 %sel = select i1 %ugt, i32 %shl, i32 1 ret i32 %sel } ; Negative test: the shl result used twice define i32 @bit_ceil_32_shl_used_twice(i32 %x, ptr %p) { ; CHECK-LABEL: @bit_ceil_32_shl_used_twice( ; CHECK-NEXT: [[DEC:%.*]] = add i32 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[DEC]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[UGT:%.*]] = icmp ugt i32 [[X]], 1 ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[UGT]], i32 [[SHL]], i32 1 ; CHECK-NEXT: store i32 [[SHL]], ptr [[P:%.*]], align 4 ; CHECK-NEXT: ret i32 [[SEL]] ; %dec = add i32 %x, -1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %dec, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %ugt = icmp ugt i32 %x, 1 %sel = select i1 %ugt, i32 %shl, i32 1 store i32 %shl, ptr %p, align 4 ret i32 %sel } ; Negative test: the sub result used twice define i32 @bit_ceil_32_sub_used_twice(i32 %x, ptr %p) { ; CHECK-LABEL: @bit_ceil_32_sub_used_twice( ; CHECK-NEXT: [[DEC:%.*]] = add i32 [[X:%.*]], -1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[DEC]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[UGT:%.*]] = icmp ugt i32 [[X]], 1 ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[UGT]], i32 [[SHL]], i32 1 ; CHECK-NEXT: store i32 [[SUB]], ptr [[P:%.*]], align 4 ; CHECK-NEXT: ret i32 [[SEL]] ; %dec = add i32 %x, -1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %dec, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %ugt = icmp ugt i32 %x, 1 %sel = select i1 %ugt, i32 %shl, i32 1 store i32 %sub, ptr %p, align 4 ret i32 %sel } ; a vector version of @bit_ceil_32 above define <4 x i32> @bit_ceil_v4i32(<4 x i32> %x) { ; CHECK-LABEL: @bit_ceil_v4i32( ; CHECK-NEXT: [[DEC:%.*]] = add <4 x i32> [[X:%.*]], ; CHECK-NEXT: [[CTLZ:%.*]] = tail call <4 x i32> @llvm.ctlz.v4i32(<4 x i32> [[DEC]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[TMP1:%.*]] = sub nsw <4 x i32> zeroinitializer, [[CTLZ]] ; CHECK-NEXT: [[TMP2:%.*]] = and <4 x i32> [[TMP1]], ; CHECK-NEXT: [[SEL:%.*]] = shl nuw <4 x i32> , [[TMP2]] ; CHECK-NEXT: ret <4 x i32> [[SEL]] ; %dec = add <4 x i32> %x, %ctlz = tail call <4 x i32> @llvm.ctlz.v4i32(<4 x i32> %dec, i1 false) %sub = sub <4 x i32> , %ctlz %shl = shl <4 x i32> , %sub %ugt = icmp ugt <4 x i32> %x, %sel = select <4 x i1> %ugt, <4 x i32> %shl, <4 x i32> ret <4 x i32> %sel } define i32 @pr91691(i32 %0) { ; CHECK-LABEL: @pr91691( ; CHECK-NEXT: [[TMP2:%.*]] = sub i32 -2, [[TMP0:%.*]] ; CHECK-NEXT: [[TMP3:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[TMP2]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[TMP4:%.*]] = sub nsw i32 0, [[TMP3]] ; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP4]], 31 ; CHECK-NEXT: [[TMP6:%.*]] = shl nuw i32 1, [[TMP5]] ; CHECK-NEXT: ret i32 [[TMP6]] ; %2 = sub nuw i32 -2, %0 %3 = tail call i32 @llvm.ctlz.i32(i32 %2, i1 false) %4 = sub i32 32, %3 %5 = shl i32 1, %4 %6 = icmp ult i32 %0, -2 %7 = select i1 %6, i32 %5, i32 1 ret i32 %7 } define i32 @pr91691_keep_nsw(i32 %0) { ; CHECK-LABEL: @pr91691_keep_nsw( ; CHECK-NEXT: [[TMP2:%.*]] = sub nsw i32 -2, [[TMP0:%.*]] ; CHECK-NEXT: [[TMP3:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[TMP2]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[TMP4:%.*]] = sub nsw i32 0, [[TMP3]] ; CHECK-NEXT: [[TMP5:%.*]] = and i32 [[TMP4]], 31 ; CHECK-NEXT: [[TMP6:%.*]] = shl nuw i32 1, [[TMP5]] ; CHECK-NEXT: ret i32 [[TMP6]] ; %2 = sub nsw i32 -2, %0 %3 = tail call i32 @llvm.ctlz.i32(i32 %2, i1 false) %4 = sub i32 32, %3 %5 = shl i32 1, %4 %6 = icmp ult i32 %0, -2 %7 = select i1 %6, i32 %5, i32 1 ret i32 %7 } declare i32 @llvm.ctlz.i32(i32, i1 immarg) declare i64 @llvm.ctlz.i64(i64, i1 immarg) declare <4 x i32> @llvm.ctlz.v4i32(<4 x i32>, i1)