; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt < %s -passes=instcombine -S | FileCheck %s define i32 @bit_floor_32(i32 %x) { ; CHECK-LABEL: @bit_floor_32( ; CHECK-NEXT: [[EQ0:%.*]] = icmp eq i32 [[X:%.*]], 0 ; CHECK-NEXT: [[LSHR:%.*]] = lshr i32 [[X]], 1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[LSHR]], i1 false), !range [[RNG0:![0-9]+]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[EQ0]], i32 0, i32 [[SHL]] ; CHECK-NEXT: ret i32 [[SEL]] ; %eq0 = icmp eq i32 %x, 0 %lshr = lshr i32 %x, 1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %lshr, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %sel = select i1 %eq0, i32 0, i32 %shl ret i32 %sel } define i64 @bit_floor_64(i64 %x) { ; CHECK-LABEL: @bit_floor_64( ; CHECK-NEXT: [[EQ0:%.*]] = icmp eq i64 [[X:%.*]], 0 ; CHECK-NEXT: [[LSHR:%.*]] = lshr i64 [[X]], 1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i64 @llvm.ctlz.i64(i64 [[LSHR]], i1 false), !range [[RNG1:![0-9]+]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i64 64, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i64 1, [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[EQ0]], i64 0, i64 [[SHL]] ; CHECK-NEXT: ret i64 [[SEL]] ; %eq0 = icmp eq i64 %x, 0 %lshr = lshr i64 %x, 1 %ctlz = tail call i64 @llvm.ctlz.i64(i64 %lshr, i1 false) %sub = sub i64 64, %ctlz %shl = shl i64 1, %sub %sel = select i1 %eq0, i64 0, i64 %shl ret i64 %sel } ; Commutted select operands should still be recognized. define i32 @bit_floor_commuted_operands(i32 %x) { ; CHECK-LABEL: @bit_floor_commuted_operands( ; CHECK-NEXT: [[NE0_NOT:%.*]] = icmp eq i32 [[X:%.*]], 0 ; CHECK-NEXT: [[LSHR:%.*]] = lshr i32 [[X]], 1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[LSHR]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[NE0_NOT]], i32 0, i32 [[SHL]] ; CHECK-NEXT: ret i32 [[SEL]] ; %ne0 = icmp ne i32 %x, 0 %lshr = lshr i32 %x, 1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %lshr, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %sel = select i1 %ne0, i32 %shl, i32 0 ret i32 %sel } ; Negative test: lshr used twice define i32 @bit_floor_lshr_used_twice(i32 %x, ptr %p) { ; CHECK-LABEL: @bit_floor_lshr_used_twice( ; CHECK-NEXT: [[EQ0:%.*]] = icmp eq i32 [[X:%.*]], 0 ; CHECK-NEXT: [[LSHR:%.*]] = lshr i32 [[X]], 1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[LSHR]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[EQ0]], i32 0, i32 [[SHL]] ; CHECK-NEXT: store i32 [[LSHR]], ptr [[P:%.*]], align 4 ; CHECK-NEXT: ret i32 [[SEL]] ; %eq0 = icmp eq i32 %x, 0 %lshr = lshr i32 %x, 1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %lshr, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %sel = select i1 %eq0, i32 0, i32 %shl store i32 %lshr, ptr %p, align 4 ret i32 %sel } ; Negative test: ctlz used twice define i32 @bit_floor_ctlz_used_twice(i32 %x, ptr %p) { ; CHECK-LABEL: @bit_floor_ctlz_used_twice( ; CHECK-NEXT: [[EQ0:%.*]] = icmp eq i32 [[X:%.*]], 0 ; CHECK-NEXT: [[LSHR:%.*]] = lshr i32 [[X]], 1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[LSHR]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[EQ0]], i32 0, i32 [[SHL]] ; CHECK-NEXT: store i32 [[CTLZ]], ptr [[P:%.*]], align 4 ; CHECK-NEXT: ret i32 [[SEL]] ; %eq0 = icmp eq i32 %x, 0 %lshr = lshr i32 %x, 1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %lshr, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %sel = select i1 %eq0, i32 0, i32 %shl store i32 %ctlz, ptr %p, align 4 ret i32 %sel } ; Negative test: sub used twice define i32 @bit_floor_sub_used_twice(i32 %x, ptr %p) { ; CHECK-LABEL: @bit_floor_sub_used_twice( ; CHECK-NEXT: [[EQ0:%.*]] = icmp eq i32 [[X:%.*]], 0 ; CHECK-NEXT: [[LSHR:%.*]] = lshr i32 [[X]], 1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[LSHR]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[EQ0]], i32 0, i32 [[SHL]] ; CHECK-NEXT: store i32 [[SUB]], ptr [[P:%.*]], align 4 ; CHECK-NEXT: ret i32 [[SEL]] ; %eq0 = icmp eq i32 %x, 0 %lshr = lshr i32 %x, 1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %lshr, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %sel = select i1 %eq0, i32 0, i32 %shl store i32 %sub, ptr %p, align 4 ret i32 %sel } ; Negative test: shl used twice define i32 @bit_floor_shl_used_twice(i32 %x, ptr %p) { ; CHECK-LABEL: @bit_floor_shl_used_twice( ; CHECK-NEXT: [[EQ0:%.*]] = icmp eq i32 [[X:%.*]], 0 ; CHECK-NEXT: [[LSHR:%.*]] = lshr i32 [[X]], 1 ; CHECK-NEXT: [[CTLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[LSHR]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw i32 32, [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw i32 1, [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select i1 [[EQ0]], i32 0, i32 [[SHL]] ; CHECK-NEXT: store i32 [[SHL]], ptr [[P:%.*]], align 4 ; CHECK-NEXT: ret i32 [[SEL]] ; %eq0 = icmp eq i32 %x, 0 %lshr = lshr i32 %x, 1 %ctlz = tail call i32 @llvm.ctlz.i32(i32 %lshr, i1 false) %sub = sub i32 32, %ctlz %shl = shl i32 1, %sub %sel = select i1 %eq0, i32 0, i32 %shl store i32 %shl, ptr %p, align 4 ret i32 %sel } ; a vector version of @bit_floor_32 above define <4 x i32> @bit_floor_v4i32(<4 x i32> %x) { ; CHECK-LABEL: @bit_floor_v4i32( ; CHECK-NEXT: [[EQ0:%.*]] = icmp eq <4 x i32> [[X:%.*]], zeroinitializer ; CHECK-NEXT: [[LSHR:%.*]] = lshr <4 x i32> [[X]], ; CHECK-NEXT: [[CTLZ:%.*]] = tail call <4 x i32> @llvm.ctlz.v4i32(<4 x i32> [[LSHR]], i1 false), !range [[RNG0]] ; CHECK-NEXT: [[SUB:%.*]] = sub nuw nsw <4 x i32> , [[CTLZ]] ; CHECK-NEXT: [[SHL:%.*]] = shl nuw <4 x i32> , [[SUB]] ; CHECK-NEXT: [[SEL:%.*]] = select <4 x i1> [[EQ0]], <4 x i32> zeroinitializer, <4 x i32> [[SHL]] ; CHECK-NEXT: ret <4 x i32> [[SEL]] ; %eq0 = icmp eq <4 x i32> %x, %lshr = lshr <4 x i32> %x, %ctlz = tail call <4 x i32> @llvm.ctlz.v4i32(<4 x i32> %lshr, i1 false) %sub = sub <4 x i32> , %ctlz %shl = shl <4 x i32> , %sub %sel = select <4 x i1> %eq0, <4 x i32> , <4 x i32> %shl ret <4 x i32> %sel } 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)