Commit e21a90f0 authored by khei4's avatar khei4
Browse files

[SimplifyCFG] add nuw/nsw on BuildLookuptable BitMap shiftwidth calculation 

Differential Revision: https://reviews.llvm.org/D150838
parent 2ef8ae13

llvm/lib/Transforms/Utils/SimplifyCFG.cpp

+4 −2
Original line number Diff line number Diff line
@@ -6129,10 +6129,12 @@ Value *SwitchLookupTable::BuildLookup(Value *Index, IRBuilder<> &Builder) { 
    // truncating it to the width of the bitmask is safe.

    Value *ShiftAmt = Builder.CreateZExtOrTrunc(Index, MapTy, "switch.cast");



    // Multiply the shift amount by the element width.

    // Multiply the shift amount by the element width. NUW/NSW can always be

    // set, because WouldFitInRegister guarantees Index * ShiftAmt is in

    // BitMap's bit width.

    ShiftAmt = Builder.CreateMul(

        ShiftAmt, ConstantInt::get(MapTy, BitMapElementTy->getBitWidth()),

        "switch.shiftamt");

        "switch.shiftamt",/*HasNUW =*/true,/*HasNSW =*/true);



    // Shift down.

    Value *DownShifted =

llvm/test/Transforms/SimplifyCFG/RISCV/switch_to_lookup_table-rv32.ll

+1 −1
Original line number Diff line number Diff line
@@ -112,7 +112,7 @@ define void @h(i32 %x) { 
; CHECK-NEXT:    [[TMP0:%.*]] = icmp ult i32 [[X:%.*]], 4

; CHECK-NEXT:    br i1 [[TMP0]], label [[SWITCH_LOOKUP:%.*]], label [[SW_EPILOG:%.*]]

; CHECK:       switch.lookup:

; CHECK-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul i32 [[X]], 8

; CHECK-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul nuw nsw i32 [[X]], 8

; CHECK-NEXT:    [[SWITCH_DOWNSHIFT:%.*]] = lshr i32 89655594, [[SWITCH_SHIFTAMT]]

; CHECK-NEXT:    [[SWITCH_MASKED:%.*]] = trunc i32 [[SWITCH_DOWNSHIFT]] to i8

; CHECK-NEXT:    [[SWITCH_GEP:%.*]] = getelementptr inbounds [4 x float], ptr @switch.table.h, i32 0, i32 [[X]]

llvm/test/Transforms/SimplifyCFG/RISCV/switch_to_lookup_table-rv64.ll

+1 −1
Original line number Diff line number Diff line
@@ -112,7 +112,7 @@ define void @h(i32 %x) { 
; CHECK-NEXT:    [[TMP0:%.*]] = icmp ult i32 [[X:%.*]], 4

; CHECK-NEXT:    br i1 [[TMP0]], label [[SWITCH_LOOKUP:%.*]], label [[SW_EPILOG:%.*]]

; CHECK:       switch.lookup:

; CHECK-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul i32 [[X]], 8

; CHECK-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul nuw nsw i32 [[X]], 8

; CHECK-NEXT:    [[SWITCH_DOWNSHIFT:%.*]] = lshr i32 89655594, [[SWITCH_SHIFTAMT]]

; CHECK-NEXT:    [[SWITCH_MASKED:%.*]] = trunc i32 [[SWITCH_DOWNSHIFT]] to i8

; CHECK-NEXT:    [[SWITCH_GEP:%.*]] = getelementptr inbounds [4 x float], ptr @switch.table.h, i32 0, i32 [[X]]

llvm/test/Transforms/SimplifyCFG/X86/CoveredLookupTable.ll

+1 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ define i3 @coveredswitch_test(i3 %input) { 
; CHECK-NEXT:  entry:

; CHECK-NEXT:    [[SWITCH_TABLEIDX:%.*]] = sub i3 [[INPUT:%.*]], -4

; CHECK-NEXT:    [[SWITCH_CAST:%.*]] = zext i3 [[SWITCH_TABLEIDX]] to i24

; CHECK-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul i24 [[SWITCH_CAST]], 3

; CHECK-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul nuw nsw i24 [[SWITCH_CAST]], 3

; CHECK-NEXT:    [[SWITCH_DOWNSHIFT:%.*]] = lshr i24 7507338, [[SWITCH_SHIFTAMT]]

; CHECK-NEXT:    [[SWITCH_MASKED:%.*]] = trunc i24 [[SWITCH_DOWNSHIFT]] to i3

; CHECK-NEXT:    ret i3 [[SWITCH_MASKED]]

llvm/test/Transforms/SimplifyCFG/X86/switch-to-lookup-large-types.ll

+2 −2
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ define i8 @switch_to_lookup_i64(i64 %x){ 
; INLINE-NEXT:  start:

; INLINE-NEXT:    [[TMP0:%.*]] = icmp ult i64 [[X:%.*]], 3

; INLINE-NEXT:    [[SWITCH_CAST:%.*]] = trunc i64 [[X]] to i24

; INLINE-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul i24 [[SWITCH_CAST]], 8

; INLINE-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul nuw nsw i24 [[SWITCH_CAST]], 8

; INLINE-NEXT:    [[SWITCH_DOWNSHIFT:%.*]] = lshr i24 131331, [[SWITCH_SHIFTAMT]]

; INLINE-NEXT:    [[SWITCH_MASKED:%.*]] = trunc i24 [[SWITCH_DOWNSHIFT]] to i8

; INLINE-NEXT:    [[COMMON_RET_OP:%.*]] = select i1 [[TMP0]], i8 [[SWITCH_MASKED]], i8 10
@@ -69,7 +69,7 @@ define i8 @switch_to_lookup_i128(i128 %x){ 
; INLINE-NEXT:  start:

; INLINE-NEXT:    [[TMP0:%.*]] = icmp ult i128 [[X:%.*]], 3

; INLINE-NEXT:    [[SWITCH_CAST:%.*]] = trunc i128 [[X]] to i24

; INLINE-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul i24 [[SWITCH_CAST]], 8

; INLINE-NEXT:    [[SWITCH_SHIFTAMT:%.*]] = mul nuw nsw i24 [[SWITCH_CAST]], 8

; INLINE-NEXT:    [[SWITCH_DOWNSHIFT:%.*]] = lshr i24 131331, [[SWITCH_SHIFTAMT]]

; INLINE-NEXT:    [[SWITCH_MASKED:%.*]] = trunc i24 [[SWITCH_DOWNSHIFT]] to i8

; INLINE-NEXT:    [[COMMON_RET_OP:%.*]] = select i1 [[TMP0]], i8 [[SWITCH_MASKED]], i8 10