; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py ; RUN: llc -mtriple=riscv64 -mattr=+m -verify-machineinstrs < %s | FileCheck %s ; This test has multiple opportunities for SimplifyDemandedBits after type ; legalization. There are 2 opportunities on the chain feeding the LHS of the ; shl. And one opportunity on the shift amount. We previously weren't managing ; the DAGCombiner worklist correctly and failed to get the RHS. define i32 @foo(i32 %x, i32 %y, i32 %z) { ; CHECK-LABEL: foo: ; CHECK: # %bb.0: ; CHECK-NEXT: mul a0, a0, a0 ; CHECK-NEXT: addi a0, a0, 1 ; CHECK-NEXT: mul a0, a0, a0 ; CHECK-NEXT: add a0, a0, a2 ; CHECK-NEXT: addi a0, a0, 1 ; CHECK-NEXT: sllw a0, a0, a1 ; CHECK-NEXT: ret %b = mul i32 %x, %x %c = add i32 %b, 1 %d = mul i32 %c, %c %e = add i32 %d, %z %f = add i32 %e, 1 %g = shl i32 %f, %y ret i32 %g } ; The sign bit of an nsw self multiply is 0. Make sure we can use this to ; convert the AND constant to -8. define i64 @mul_self_nsw_sign(i64 %x) { ; CHECK-LABEL: mul_self_nsw_sign: ; CHECK: # %bb.0: ; CHECK-NEXT: mul a0, a0, a0 ; CHECK-NEXT: andi a0, a0, -8 ; CHECK-NEXT: ret %a = mul nsw i64 %x, %x %b = and i64 %a, 9223372036854775800 ret i64 %b } ; Make sure we sign extend the constant after type legalization to allow the ; use of ori. define void @ori(ptr nocapture noundef %0) { ; CHECK-LABEL: ori: ; CHECK: # %bb.0: ; CHECK-NEXT: lw a1, 0(a0) ; CHECK-NEXT: ori a1, a1, -2 ; CHECK-NEXT: sw a1, 0(a0) ; CHECK-NEXT: ret %2 = load i32, ptr %0, align 4 %3 = or i32 %2, -2 store i32 %3, ptr %0, align 4 ret void } ; Make sure we sign extend the constant after type legalization to allow the ; use of xori. define void @xori(ptr nocapture noundef %0) { ; CHECK-LABEL: xori: ; CHECK: # %bb.0: ; CHECK-NEXT: lw a1, 0(a0) ; CHECK-NEXT: xori a1, a1, -5 ; CHECK-NEXT: sw a1, 0(a0) ; CHECK-NEXT: ret %2 = load i32, ptr %0, align 4 %3 = xor i32 %2, -5 store i32 %3, ptr %0, align 4 ret void } ; Make sure we sign extend the constant after type legalization to allow the ; shorter constant materialization. define void @or_signbit(ptr nocapture noundef %0) { ; CHECK-LABEL: or_signbit: ; CHECK: # %bb.0: ; CHECK-NEXT: lw a1, 0(a0) ; CHECK-NEXT: lui a2, 524288 ; CHECK-NEXT: or a1, a1, a2 ; CHECK-NEXT: sw a1, 0(a0) ; CHECK-NEXT: ret %2 = load i32, ptr %0, align 4 %3 = or i32 %2, -2147483648 store i32 %3, ptr %0, align 4 ret void } ; Make sure we sign extend the constant after type legalization to allow the ; shorter constant materialization. define void @xor_signbit(ptr nocapture noundef %0) { ; CHECK-LABEL: xor_signbit: ; CHECK: # %bb.0: ; CHECK-NEXT: lw a1, 0(a0) ; CHECK-NEXT: lui a2, 524288 ; CHECK-NEXT: xor a1, a1, a2 ; CHECK-NEXT: sw a1, 0(a0) ; CHECK-NEXT: ret %2 = load i32, ptr %0, align 4 %3 = xor i32 %2, -2147483648 store i32 %3, ptr %0, align 4 ret void } ; Type legalization inserts a sext_inreg after the sub. This causes the ; constant for the AND to be turned into 0xfffffff8. Then SimplifyDemandedBits ; removes the sext_inreg from the path to the store. This prevents ; TargetShrinkDemandedConstant from being able to restore the lost upper bits ; from the and mask to allow andi. ISel is able to recover the lost sext_inreg ; using hasAllWUsers. We also use hasAllWUsers to recover the ANDI. define signext i32 @andi_sub_cse(i32 signext %0, i32 signext %1, ptr %2) { ; CHECK-LABEL: andi_sub_cse: ; CHECK: # %bb.0: ; CHECK-NEXT: andi a0, a0, -8 ; CHECK-NEXT: subw a0, a0, a1 ; CHECK-NEXT: sw a0, 0(a2) ; CHECK-NEXT: ret %4 = and i32 %0, -8 %5 = sub i32 %4, %1 store i32 %5, ptr %2, align 4 ret i32 %5 } define signext i32 @addi_sub_cse(i32 signext %0, i32 signext %1, ptr %2) { ; CHECK-LABEL: addi_sub_cse: ; CHECK: # %bb.0: ; CHECK-NEXT: subw a0, a0, a1 ; CHECK-NEXT: addiw a0, a0, -8 ; CHECK-NEXT: sw a0, 0(a2) ; CHECK-NEXT: ret %4 = add i32 %0, -8 %5 = sub i32 %4, %1 store i32 %5, ptr %2, align 4 ret i32 %5 } define signext i32 @xori_sub_cse(i32 signext %0, i32 signext %1, ptr %2) { ; CHECK-LABEL: xori_sub_cse: ; CHECK: # %bb.0: ; CHECK-NEXT: xori a0, a0, -8 ; CHECK-NEXT: subw a0, a0, a1 ; CHECK-NEXT: sw a0, 0(a2) ; CHECK-NEXT: ret %4 = xor i32 %0, -8 %5 = sub i32 %4, %1 store i32 %5, ptr %2, align 4 ret i32 %5 } define signext i32 @ori_sub_cse(i32 signext %0, i32 signext %1, ptr %2) { ; CHECK-LABEL: ori_sub_cse: ; CHECK: # %bb.0: ; CHECK-NEXT: ori a0, a0, -8 ; CHECK-NEXT: subw a0, a0, a1 ; CHECK-NEXT: sw a0, 0(a2) ; CHECK-NEXT: ret %4 = or i32 %0, -8 %5 = sub i32 %4, %1 store i32 %5, ptr %2, align 4 ret i32 %5 } ; SimplifyDemandedBits breaks the ANDI by turning -8 into 0xfffffff8. This ; gets CSEd with the AND needed for type legalizing the lshr. This increases ; the use count of the AND with 0xfffffff8 making TargetShrinkDemandedConstant ; unable to restore it to 0xffffffff for the lshr and -8 for the AND to use ; ANDI. ; Instead we rely on ISel to form srliw even though the AND has multiple uses ; and the mask has missing 1s where bits will be shifted out. This reduces the ; use count of the AND and we can use hasAllWUsers to form ANDI. define signext i32 @andi_srliw(i32 signext %0, ptr %1, i32 signext %2) { ; CHECK-LABEL: andi_srliw: ; CHECK: # %bb.0: ; CHECK-NEXT: andi a3, a0, -8 ; CHECK-NEXT: srliw a4, a0, 3 ; CHECK-NEXT: addw a0, a3, a2 ; CHECK-NEXT: sw a4, 0(a1) ; CHECK-NEXT: ret %4 = and i32 %0, -8 %5 = lshr i32 %0, 3 store i32 %5, ptr %1, align 4 %6 = add i32 %4, %2 ret i32 %6 } define i32 @and_or(i32 signext %x) { ; CHECK-LABEL: and_or: ; CHECK: # %bb.0: # %entry ; CHECK-NEXT: ori a0, a0, 255 ; CHECK-NEXT: slli a0, a0, 48 ; CHECK-NEXT: srli a0, a0, 48 ; CHECK-NEXT: ret entry: %and = and i32 %x, 65280 %or = or i32 %and, 255 ret i32 %or }