| ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py |
| ; RUN: opt < %s -reassociate -S | FileCheck %s |
| |
| define i32 @shl_add(i8 %x) { |
| ; CHECK-LABEL: @shl_add( |
| ; CHECK-NEXT: [[CONV:%.*]] = zext i8 [[X:%.*]] to i32 |
| ; CHECK-NEXT: [[SHL:%.*]] = shl nuw nsw i32 [[CONV]], 8 |
| ; CHECK-NEXT: [[SHL2:%.*]] = shl nuw nsw i32 [[CONV]], 16 |
| ; CHECK-NEXT: [[ADD:%.*]] = add nuw nsw i32 [[SHL]], [[SHL2]] |
| ; CHECK-NEXT: ret i32 [[ADD]] |
| ; |
| %conv = zext i8 %x to i32 |
| %shl = shl nuw nsw i32 %conv, 8 |
| %shl2 = shl nuw nsw i32 %conv, 16 |
| %add = or i32 %shl, %shl2 |
| ret i32 %add |
| } |
| |
| ; If we don't know that operands have no common bits set, |
| ; we can't convert the `or` into an `add`. |
| define i32 @test1(i32 %a, i32 %b) { |
| ; CHECK-LABEL: @test1( |
| ; CHECK-NEXT: [[C:%.*]] = or i32 [[B:%.*]], [[A:%.*]] |
| ; CHECK-NEXT: [[C_PLUS_ONE:%.*]] = add i32 [[C]], 1 |
| ; CHECK-NEXT: ret i32 [[C_PLUS_ONE]] |
| ; |
| %c = or i32 %a, %b |
| %c.plus.one = add i32 %c, 1 |
| ret i32 %c.plus.one |
| } |
| |
| ; But if we *do* know that operands have no common bits set, |
| ; we *can* convert the `or` into an `add`. |
| define i32 @test2(i32 %x, i32 %y) { |
| ; CHECK-LABEL: @test2( |
| ; CHECK-NEXT: [[X_NUMLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 true), [[RNG0:!range !.*]] |
| ; CHECK-NEXT: [[RES:%.*]] = add nuw nsw i32 [[X_NUMLZ]], -32 |
| ; CHECK-NEXT: [[RES_PLUS_ONE:%.*]] = add i32 [[RES]], [[Y:%.*]] |
| ; CHECK-NEXT: ret i32 [[RES_PLUS_ONE]] |
| ; |
| %x.numlz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true), !range !0 |
| %res = or i32 %x.numlz, -32 |
| %res.plus.one = add i32 %res, %y |
| ret i32 %res.plus.one |
| } |
| |
| ; And that allows reassociation in general. |
| define i32 @test3(i32 %x, i32 %bit) { |
| ; CHECK-LABEL: @test3( |
| ; CHECK-NEXT: [[X_NUMLZ:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 true), [[RNG0]] |
| ; CHECK-NEXT: [[BIT_PLUS_ONE:%.*]] = add i32 [[BIT:%.*]], -31 |
| ; CHECK-NEXT: [[RES:%.*]] = add i32 [[BIT_PLUS_ONE]], [[X_NUMLZ]] |
| ; CHECK-NEXT: ret i32 [[RES]] |
| ; |
| %x.numlz = tail call i32 @llvm.ctlz.i32(i32 %x, i1 true), !range !0 |
| %zero.minus.x.numactivebits = or i32 %x.numlz, -32 |
| %bit.plus.one = add i32 %bit, 1 |
| %res = add i32 %bit.plus.one, %zero.minus.x.numactivebits |
| ret i32 %res |
| } |
| |
| declare i32 @llvm.ctlz.i32(i32, i1 immarg) #2 |
| |
| !0 = !{i32 0, i32 33} |