[GlobalISel] Combine for eliminating redundant operand negations

[foad]

llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h

620–622

Are these definitely safe. even with signed zeros? Does SelectionDAG do the same?

625

Typo "fma".

[mbrkusanin]

• Fix comments + rebase

llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h

620–622

SelectionDAG does not have any extra checks for these specific combines (unlike for some others) so I assume it's safe.
Equivalent SDAG combines are in DAGCombiner::visitFADD and DAGCombiner::visitFSUB.

[foad]

LGTM.

llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h

public:
   ///       and rename: s/bool tryEmit/void emit/
   bool tryEmitMemcpyInline(MachineInstr &MI);
 
   /// Match:
   ///   (G_UMULO x, 2) -> (G_UADDO x, x)
   ///   (G_SMULO x, 2) -> (G_SADDO x, x)
   bool matchMulOBy2(MachineInstr &MI, BuildFnTy &MatchInfo);
 
+  /// Transform (fadd x, fneg(y)) -> (fsub x, y)
+  ///           (fadd fneg(x), y) -> (fsub y, x)
+  ///           (fsub x, fneg(y)) -> (fadd x, y)
+  ///           (fmul fneg(x), fneg(y)) -> (fmul x, y)
+  ///           (fdiv fneg(x), fneg(y)) -> (fdiv x, y)
+  ///           (fmad fneg(x), fneg(y), z) -> (fma x, y, z)
+  ///           (fma fneg(x), fneg(y), z) -> (fma x, y, z)
+  bool matchRedundantNegOperands(MachineInstr &MI, BuildFnTy &MatchInfo);
+
 private:
   /// Given a non-indexed load or store instruction \p MI, find an offset that
   /// can be usefully and legally folded into it as a post-indexing operation.
   ///
   /// \returns true if a candidate is found.
   bool findPostIndexCandidate(MachineInstr &MI, Register &Addr, Register &Base,
                               Register &Offset);
 

llvm/include/llvm/Target/GlobalISel/Combine.td

def constant_fold : GICombineRule<
   (apply [{ Helper.replaceInstWithConstant(*${d}, ${matchinfo}); }])>;
 
 def mulo_by_2: GICombineRule<
   (defs root:$root, build_fn_matchinfo:$matchinfo),
   (match (wip_match_opcode G_UMULO, G_SMULO):$root,
          [{ return Helper.matchMulOBy2(*${root}, ${matchinfo}); }]),
   (apply [{ Helper.applyBuildFnNoErase(*${root}, ${matchinfo}); }])>;
 
+def redundant_neg_operands: GICombineRule<
+  (defs root:$root, build_fn_matchinfo:$matchinfo),
+  (match (wip_match_opcode G_FADD, G_FSUB, G_FMUL, G_FDIV, G_FMAD, G_FMA):$root,
+    [{ return Helper.matchRedundantNegOperands(*${root}, ${matchinfo}); }]),
+  (apply [{ Helper.applyBuildFnNoErase(*${root}, ${matchinfo}); }])>;
+
 // FIXME: These should use the custom predicate feature once it lands.
 def undef_combines : GICombineGroup<[undef_to_fp_zero, undef_to_int_zero,
                                      undef_to_negative_one,
                                      binop_left_undef_to_zero,
                                      propagate_undef_any_op,
                                      propagate_undef_all_ops,
                                      propagate_undef_shuffle_mask,
                                      erase_undef_store]>;
def all_combines : GICombineGroup<[trivial_combines, insert_vec_elt_combines,
     width_reduction_combines, select_combines,
     known_bits_simplifications, ext_ext_fold,
     not_cmp_fold, opt_brcond_by_inverting_cond,
     unmerge_merge, fabs_fabs_fold, unmerge_cst, unmerge_dead_to_trunc,
     unmerge_zext_to_zext, merge_unmerge, trunc_ext_fold, trunc_shl,
     const_combines, xor_of_and_with_same_reg, ptr_add_with_zero,
     shift_immed_chain, shift_of_shifted_logic_chain, load_or_combine,
     truncstore_merge, div_rem_to_divrem, funnel_shift_combines,
-    form_bitfield_extract, constant_fold, fabs_fneg_fold]>;
+    form_bitfield_extract, constant_fold, fabs_fneg_fold,
+    redundant_neg_operands]>;
 
 // A combine group used to for prelegalizer combiners at -O0. The combines in
 // this group have been selected based on experiments to balance code size and
 // compile time performance.
 def optnone_combines : GICombineGroup<[trivial_combines,
     ptr_add_immed_chain, combines_for_extload,
     not_cmp_fold, opt_brcond_by_inverting_cond]>;

llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp

unsigned NewOpc = Opc == TargetOpcode::G_UMULO ? TargetOpcode::G_UADDO
                                                    : TargetOpcode::G_SADDO;
     MI.setDesc(Builder.getTII().get(NewOpc));
     MI.getOperand(3).setReg(MI.getOperand(2).getReg());
     Observer.changedInstr(MI);
   };
   return true;
 }
 
+bool CombinerHelper::matchRedundantNegOperands(MachineInstr &MI,
+                                               BuildFnTy &MatchInfo) {
+  unsigned Opc = MI.getOpcode();
+  assert(Opc == TargetOpcode::G_FADD || Opc == TargetOpcode::G_FSUB ||
+         Opc == TargetOpcode::G_FMUL || Opc == TargetOpcode::G_FDIV ||
+         Opc == TargetOpcode::G_FMAD || Opc == TargetOpcode::G_FMA);
+
+  Register Dst = MI.getOperand(0).getReg();
+  Register X = MI.getOperand(1).getReg();
+  Register Y = MI.getOperand(2).getReg();
+  LLT Type = MRI.getType(Dst);
+
+  // fold (fadd x, fneg(y)) -> (fsub x, y)
+  // fold (fadd fneg(y), x) -> (fsub x, y)
+  // G_ADD is commutative so both cases are checked by m_GFAdd
+  if (mi_match(Dst, MRI, m_GFAdd(m_Reg(X), m_GFNeg(m_Reg(Y)))) &&
+      isLegalOrBeforeLegalizer({TargetOpcode::G_FSUB, {Type}})) {
+    Opc = TargetOpcode::G_FSUB;
+  }
+  /// fold (fsub x, fneg(y)) -> (fadd x, y)
+  else if (mi_match(Dst, MRI, m_GFSub(m_Reg(X), m_GFNeg(m_Reg(Y)))) &&
+           isLegalOrBeforeLegalizer({TargetOpcode::G_FADD, {Type}})) {
+    Opc = TargetOpcode::G_FADD;
+  }
+  // fold (fmul fneg(x), fneg(y)) -> (fmul x, y)
+  // fold (fdiv fneg(x), fneg(y)) -> (fdiv x, y)
+  // fold (fmad fneg(x), fneg(y), z) -> (fma x, y, z)
+  // fold (fma fneg(x), fneg(y), z) -> (fma x, y, z)
+  else if ((Opc == TargetOpcode::G_FMUL || Opc == TargetOpcode::G_FDIV ||
+            Opc == TargetOpcode::G_FMAD || Opc == TargetOpcode::G_FMA) &&
+           (mi_match(X, MRI, m_GFNeg(m_Reg(X))) &&
+            mi_match(Y, MRI, m_GFNeg(m_Reg(Y))))) {
+    // no opcode change
+  } else
+    return false;
+
+  MatchInfo = [=, &MI](MachineIRBuilder &B) {
+    Observer.changingInstr(MI);
+    MI.setDesc(B.getTII().get(Opc));
+    MI.getOperand(1).setReg(X);
+    MI.getOperand(2).setReg(Y);
+    Observer.changedInstr(MI);
+  };
+  return true;
+}
+
 bool CombinerHelper::tryCombine(MachineInstr &MI) {
   if (tryCombineCopy(MI))
     return true;
   if (tryCombineExtendingLoads(MI))
     return true;
   if (tryCombineIndexedLoadStore(MI))
     return true;
   return false;
 }

llvm/test/CodeGen/AMDGPU/GlobalISel/combine-redundant-neg.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -march=amdgcn -run-pass=amdgpu-prelegalizer-combiner -verify-machineinstrs %s -o - | FileCheck %s
+
+---
+name:            test_add_rhs
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1
+
+    ; CHECK-LABEL: name: test_add_rhs
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1
+    ; CHECK-NEXT: [[FSUB:%[0-9]+]]:_(s32) = G_FSUB [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FSUB]](s32)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s32) = G_FNEG %1
+    %3:_(s32) = G_FADD %0, %2
+    $vgpr0 = COPY %3(s32)
+
+...
+---
+name:            test_add_lhs
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1
+
+    ; CHECK-LABEL: name: test_add_lhs
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1
+    ; CHECK-NEXT: [[FSUB:%[0-9]+]]:_(s32) = G_FSUB [[COPY1]], [[COPY]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FSUB]](s32)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s32) = G_FNEG %0
+    %3:_(s32) = G_FADD %2, %1
+    $vgpr0 = COPY %3(s32)
+
+...
+---
+name:            test_sub
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1
+
+    ; CHECK-LABEL: name: test_sub
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1
+    ; CHECK-NEXT: [[FADD:%[0-9]+]]:_(s32) = G_FADD [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FADD]](s32)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s32) = G_FNEG %1
+    %3:_(s32) = G_FSUB %0, %2
+    $vgpr0 = COPY %3(s32)
+
+...
+---
+name:            test_mul
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1
+
+    ; CHECK-LABEL: name: test_mul
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1
+    ; CHECK-NEXT: [[FMUL:%[0-9]+]]:_(s32) = G_FMUL [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FMUL]](s32)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s32) = G_FNEG %0
+    %3:_(s32) = G_FNEG %1
+    %4:_(s32) = G_FMUL %2, %3
+    $vgpr0 = COPY %4(s32)
+
+...
+---
+name:            test_div
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1
+
+    ; CHECK-LABEL: name: test_div
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1
+    ; CHECK-NEXT: [[FDIV:%[0-9]+]]:_(s32) = G_FDIV [[COPY]], [[COPY1]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FDIV]](s32)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s32) = G_FNEG %0
+    %3:_(s32) = G_FNEG %1
+    %4:_(s32) = G_FDIV %2, %3
+    $vgpr0 = COPY %4(s32)
+
+...
+---
+name:            test_fmad
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1, $vgpr2
+
+    ; CHECK-LABEL: name: test_fmad
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:_(s32) = COPY $vgpr2
+    ; CHECK-NEXT: [[FMAD:%[0-9]+]]:_(s32) = G_FMAD [[COPY]], [[COPY1]], [[COPY2]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FMAD]](s32)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s32) = COPY $vgpr2
+    %3:_(s32) = G_FNEG %0
+    %4:_(s32) = G_FNEG %1
+    %5:_(s32) = G_FMAD %3, %4, %2
+    $vgpr0 = COPY %5(s32)
+
+...
+---
+name:            test_fma
+body:             |
+  bb.0:
+    liveins: $vgpr0, $vgpr1, $vgpr2
+
+    ; CHECK-LABEL: name: test_fma
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[COPY1:%[0-9]+]]:_(s32) = COPY $vgpr1
+    ; CHECK-NEXT: [[COPY2:%[0-9]+]]:_(s32) = COPY $vgpr2
+    ; CHECK-NEXT: [[FMA:%[0-9]+]]:_(s32) = G_FMA [[COPY]], [[COPY1]], [[COPY2]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FMA]](s32)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s32) = COPY $vgpr2
+    %3:_(s32) = G_FNEG %0
+    %4:_(s32) = G_FNEG %1
+    %5:_(s32) = G_FMA %3, %4, %2
+    $vgpr0 = COPY %5(s32)
+
+...

llvm/test/CodeGen/AMDGPU/GlobalISel/fma.ll

; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %fma = call <2 x half> @llvm.fma.v2f16(<2 x half> %x, <2 x half> %y.fneg, <2 x half> %z)
   ret <2 x half> %fma
 }
 
 define <2 x half> @v_fma_v2f16_fneg_lhs_rhs(<2 x half> %x, <2 x half> %y, <2 x half> %z) {
 ; GFX6-LABEL: v_fma_v2f16_fneg_lhs_rhs:
 ; GFX6:       ; %bb.0:
 ; GFX6-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX6-NEXT:    v_mov_b32_e32 v6, 0xffff
-; GFX6-NEXT:    v_lshlrev_b32_e32 v1, 16, v1
-; GFX6-NEXT:    v_and_b32_e32 v0, v0, v6
-; GFX6-NEXT:    v_or_b32_e32 v0, v1, v0
-; GFX6-NEXT:    v_lshlrev_b32_e32 v1, 16, v3
-; GFX6-NEXT:    v_and_b32_e32 v2, v2, v6
-; GFX6-NEXT:    v_or_b32_e32 v1, v1, v2
-; GFX6-NEXT:    s_mov_b32 s4, 0x80008000
-; GFX6-NEXT:    v_xor_b32_e32 v0, s4, v0
-; GFX6-NEXT:    v_xor_b32_e32 v1, s4, v1
-; GFX6-NEXT:    v_lshrrev_b32_e32 v2, 16, v0
-; GFX6-NEXT:    v_lshrrev_b32_e32 v3, 16, v1
 ; GFX6-NEXT:    v_cvt_f32_f16_e32 v0, v0
-; GFX6-NEXT:    v_cvt_f32_f16_e32 v1, v1
-; GFX6-NEXT:    v_cvt_f32_f16_e32 v4, v4
 ; GFX6-NEXT:    v_cvt_f32_f16_e32 v2, v2
+; GFX6-NEXT:    v_cvt_f32_f16_e32 v4, v4
+; GFX6-NEXT:    v_cvt_f32_f16_e32 v1, v1
 ; GFX6-NEXT:    v_cvt_f32_f16_e32 v3, v3
 ; GFX6-NEXT:    v_cvt_f32_f16_e32 v5, v5
-; GFX6-NEXT:    v_fma_f32 v0, v0, v1, v4
+; GFX6-NEXT:    v_fma_f32 v0, v0, v2, v4
 ; GFX6-NEXT:    v_cvt_f16_f32_e32 v0, v0
-; GFX6-NEXT:    v_fma_f32 v1, v2, v3, v5
+; GFX6-NEXT:    v_fma_f32 v1, v1, v3, v5
 ; GFX6-NEXT:    v_cvt_f16_f32_e32 v1, v1
 ; GFX6-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX8-LABEL: v_fma_v2f16_fneg_lhs_rhs:
 ; GFX8:       ; %bb.0:
 ; GFX8-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX8-NEXT:    s_mov_b32 s4, 0x80008000
-; GFX8-NEXT:    v_xor_b32_e32 v0, s4, v0
-; GFX8-NEXT:    v_xor_b32_e32 v1, s4, v1
 ; GFX8-NEXT:    v_lshrrev_b32_e32 v3, 16, v0
 ; GFX8-NEXT:    v_lshrrev_b32_e32 v4, 16, v1
 ; GFX8-NEXT:    v_lshrrev_b32_e32 v5, 16, v2
 ; GFX8-NEXT:    v_fma_f16 v0, v0, v1, v2
 ; GFX8-NEXT:    v_fma_f16 v1, v3, v4, v5
 ; GFX8-NEXT:    v_mov_b32_e32 v2, 16
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v1, v2, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_or_b32_sdwa v0, v0, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX9-LABEL: v_fma_v2f16_fneg_lhs_rhs:
 ; GFX9:       ; %bb.0:
 ; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-NEXT:    v_pk_fma_f16 v0, v0, v1, v2 neg_lo:[1,1,0] neg_hi:[1,1,0]
+; GFX9-NEXT:    v_pk_fma_f16 v0, v0, v1, v2
 ; GFX9-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX10-LABEL: v_fma_v2f16_fneg_lhs_rhs:
 ; GFX10:       ; %bb.0:
 ; GFX10-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX10-NEXT:    s_waitcnt_vscnt null, 0x0
-; GFX10-NEXT:    v_pk_fma_f16 v0, v0, v1, v2 neg_lo:[1,1,0] neg_hi:[1,1,0]
+; GFX10-NEXT:    v_pk_fma_f16 v0, v0, v1, v2
 ; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %x.fneg = fneg <2 x half> %x
   %y.fneg = fneg <2 x half> %y
   %fma = call <2 x half> @llvm.fma.v2f16(<2 x half> %x.fneg, <2 x half> %y.fneg, <2 x half> %z)
   ret <2 x half> %fma
 }
 
 ; FIXME:
; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %fma = call double @llvm.fma.f64(double %x, double %y, double %z)
   ret double %fma
 }
 
 define double @v_fma_f64_fneg_all(double %x, double %y, double %z) {
 ; GFX6-LABEL: v_fma_f64_fneg_all:
 ; GFX6:       ; %bb.0:
 ; GFX6-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX6-NEXT:    v_fma_f64 v[0:1], -v[0:1], -v[2:3], -v[4:5]
+; GFX6-NEXT:    v_fma_f64 v[0:1], v[0:1], v[2:3], -v[4:5]
 ; GFX6-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX8-LABEL: v_fma_f64_fneg_all:
 ; GFX8:       ; %bb.0:
 ; GFX8-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX8-NEXT:    v_fma_f64 v[0:1], -v[0:1], -v[2:3], -v[4:5]
+; GFX8-NEXT:    v_fma_f64 v[0:1], v[0:1], v[2:3], -v[4:5]
 ; GFX8-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX9-LABEL: v_fma_f64_fneg_all:
 ; GFX9:       ; %bb.0:
 ; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-NEXT:    v_fma_f64 v[0:1], -v[0:1], -v[2:3], -v[4:5]
+; GFX9-NEXT:    v_fma_f64 v[0:1], v[0:1], v[2:3], -v[4:5]
 ; GFX9-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX10-LABEL: v_fma_f64_fneg_all:
 ; GFX10:       ; %bb.0:
 ; GFX10-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX10-NEXT:    s_waitcnt_vscnt null, 0x0
-; GFX10-NEXT:    v_fma_f64 v[0:1], -v[0:1], -v[2:3], -v[4:5]
+; GFX10-NEXT:    v_fma_f64 v[0:1], v[0:1], v[2:3], -v[4:5]
 ; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %neg.x = fneg double %x
   %neg.y = fneg double %y
   %neg.z = fneg double %z
   %fma = call double @llvm.fma.f64(double %neg.x, double %neg.y, double %neg.z)
   ret double %fma
 }
 

llvm/test/CodeGen/AMDGPU/GlobalISel/fmul.v2f16.ll

; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %mul = fmul <2 x half> %a, %neg.b
   ret <2 x half> %mul
 }
 
 define <2 x half> @v_fmul_v2f16_fneg_lhs_fneg_rhs(<2 x half> %a, <2 x half> %b) {
 ; GFX9-LABEL: v_fmul_v2f16_fneg_lhs_fneg_rhs:
 ; GFX9:       ; %bb.0:
 ; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-NEXT:    v_pk_mul_f16 v0, v0, v1 neg_lo:[1,1] neg_hi:[1,1]
+; GFX9-NEXT:    v_pk_mul_f16 v0, v0, v1
 ; GFX9-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX8-LABEL: v_fmul_v2f16_fneg_lhs_fneg_rhs:
 ; GFX8:       ; %bb.0:
 ; GFX8-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX8-NEXT:    s_mov_b32 s4, 0x80008000
-; GFX8-NEXT:    v_xor_b32_e32 v0, s4, v0
-; GFX8-NEXT:    v_xor_b32_e32 v1, s4, v1
 ; GFX8-NEXT:    v_mul_f16_e32 v2, v0, v1
 ; GFX8-NEXT:    v_mul_f16_sdwa v0, v0, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mov_b32_e32 v1, 16
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v0, v1, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_or_b32_sdwa v0, v2, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX10-LABEL: v_fmul_v2f16_fneg_lhs_fneg_rhs:
 ; GFX10:       ; %bb.0:
 ; GFX10-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX10-NEXT:    s_waitcnt_vscnt null, 0x0
-; GFX10-NEXT:    v_pk_mul_f16 v0, v0, v1 neg_lo:[1,1] neg_hi:[1,1]
+; GFX10-NEXT:    v_pk_mul_f16 v0, v0, v1
 ; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %neg.a = fneg <2 x half> %a
   %neg.b = fneg <2 x half> %b
   %mul = fmul <2 x half> %neg.a, %neg.b
   ret <2 x half> %mul
 }
 
 ; FIXME
; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %mul = fmul <4 x half> %a, %neg.b
   ret <4 x half> %mul
 }
 
 define <4 x half> @v_fmul_v4f16_fneg_lhs_fneg_rhs(<4 x half> %a, <4 x half> %b) {
 ; GFX9-LABEL: v_fmul_v4f16_fneg_lhs_fneg_rhs:
 ; GFX9:       ; %bb.0:
 ; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-NEXT:    v_pk_mul_f16 v0, v0, v2 neg_lo:[1,1] neg_hi:[1,1]
-; GFX9-NEXT:    v_pk_mul_f16 v1, v1, v3 neg_lo:[1,1] neg_hi:[1,1]
+; GFX9-NEXT:    v_pk_mul_f16 v0, v0, v2
+; GFX9-NEXT:    v_pk_mul_f16 v1, v1, v3
 ; GFX9-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX8-LABEL: v_fmul_v4f16_fneg_lhs_fneg_rhs:
 ; GFX8:       ; %bb.0:
 ; GFX8-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX8-NEXT:    s_mov_b32 s4, 0x80008000
-; GFX8-NEXT:    v_xor_b32_e32 v0, s4, v0
-; GFX8-NEXT:    v_xor_b32_e32 v1, s4, v1
-; GFX8-NEXT:    v_xor_b32_e32 v2, s4, v2
-; GFX8-NEXT:    v_xor_b32_e32 v3, s4, v3
 ; GFX8-NEXT:    v_mul_f16_e32 v4, v0, v2
 ; GFX8-NEXT:    v_mul_f16_sdwa v0, v0, v2 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mul_f16_e32 v2, v1, v3
 ; GFX8-NEXT:    v_mul_f16_sdwa v1, v1, v3 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mov_b32_e32 v3, 16
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v0, v3, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v1, v3, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_or_b32_sdwa v0, v4, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    v_or_b32_sdwa v1, v2, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX10-LABEL: v_fmul_v4f16_fneg_lhs_fneg_rhs:
 ; GFX10:       ; %bb.0:
 ; GFX10-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX10-NEXT:    s_waitcnt_vscnt null, 0x0
-; GFX10-NEXT:    v_pk_mul_f16 v0, v0, v2 neg_lo:[1,1] neg_hi:[1,1]
-; GFX10-NEXT:    v_pk_mul_f16 v1, v1, v3 neg_lo:[1,1] neg_hi:[1,1]
+; GFX10-NEXT:    v_pk_mul_f16 v0, v0, v2
+; GFX10-NEXT:    v_pk_mul_f16 v1, v1, v3
 ; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %neg.a = fneg <4 x half> %a
   %neg.b = fneg <4 x half> %b
   %mul = fmul <4 x half> %neg.a, %neg.b
   ret <4 x half> %mul
 }
 
 define <6 x half> @v_fmul_v6f16(<6 x half> %a, <6 x half> %b) {
; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %mul = fmul <6 x half> %a, %neg.b
   ret <6 x half> %mul
 }
 
 define <6 x half> @v_fmul_v6f16_fneg_lhs_fneg_rhs(<6 x half> %a, <6 x half> %b) {
 ; GFX9-LABEL: v_fmul_v6f16_fneg_lhs_fneg_rhs:
 ; GFX9:       ; %bb.0:
 ; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-NEXT:    v_pk_mul_f16 v0, v0, v3 neg_lo:[1,1] neg_hi:[1,1]
-; GFX9-NEXT:    v_pk_mul_f16 v1, v1, v4 neg_lo:[1,1] neg_hi:[1,1]
-; GFX9-NEXT:    v_pk_mul_f16 v2, v2, v5 neg_lo:[1,1] neg_hi:[1,1]
+; GFX9-NEXT:    v_pk_mul_f16 v0, v0, v3
+; GFX9-NEXT:    v_pk_mul_f16 v1, v1, v4
+; GFX9-NEXT:    v_pk_mul_f16 v2, v2, v5
 ; GFX9-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX8-LABEL: v_fmul_v6f16_fneg_lhs_fneg_rhs:
 ; GFX8:       ; %bb.0:
 ; GFX8-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX8-NEXT:    s_mov_b32 s4, 0x80008000
-; GFX8-NEXT:    v_xor_b32_e32 v0, s4, v0
-; GFX8-NEXT:    v_xor_b32_e32 v1, s4, v1
-; GFX8-NEXT:    v_xor_b32_e32 v2, s4, v2
-; GFX8-NEXT:    v_xor_b32_e32 v3, s4, v3
-; GFX8-NEXT:    v_xor_b32_e32 v4, s4, v4
-; GFX8-NEXT:    v_xor_b32_e32 v5, s4, v5
 ; GFX8-NEXT:    v_mul_f16_e32 v6, v0, v3
 ; GFX8-NEXT:    v_mul_f16_sdwa v0, v0, v3 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mul_f16_e32 v3, v1, v4
 ; GFX8-NEXT:    v_mul_f16_sdwa v1, v1, v4 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mul_f16_e32 v4, v2, v5
 ; GFX8-NEXT:    v_mul_f16_sdwa v2, v2, v5 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mov_b32_e32 v5, 16
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v1, v5, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_or_b32_sdwa v1, v3, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    v_mov_b32_e32 v3, 16
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v0, v5, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v2, v3, v2 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_or_b32_sdwa v0, v6, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    v_or_b32_sdwa v2, v4, v2 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX10-LABEL: v_fmul_v6f16_fneg_lhs_fneg_rhs:
 ; GFX10:       ; %bb.0:
 ; GFX10-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX10-NEXT:    s_waitcnt_vscnt null, 0x0
-; GFX10-NEXT:    v_pk_mul_f16 v0, v0, v3 neg_lo:[1,1] neg_hi:[1,1]
-; GFX10-NEXT:    v_pk_mul_f16 v1, v1, v4 neg_lo:[1,1] neg_hi:[1,1]
-; GFX10-NEXT:    v_pk_mul_f16 v2, v2, v5 neg_lo:[1,1] neg_hi:[1,1]
+; GFX10-NEXT:    v_pk_mul_f16 v0, v0, v3
+; GFX10-NEXT:    v_pk_mul_f16 v1, v1, v4
+; GFX10-NEXT:    v_pk_mul_f16 v2, v2, v5
 ; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %neg.a = fneg <6 x half> %a
   %neg.b = fneg <6 x half> %b
   %mul = fmul <6 x half> %neg.a, %neg.b
   ret <6 x half> %mul
 }
 
 define <8 x half> @v_fmul_v8f16(<8 x half> %a, <8 x half> %b) {
; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %mul = fmul <8 x half> %a, %neg.b
   ret <8 x half> %mul
 }
 
 define <8 x half> @v_fmul_v8f16_fneg_lhs_fneg_rhs(<8 x half> %a, <8 x half> %b) {
 ; GFX9-LABEL: v_fmul_v8f16_fneg_lhs_fneg_rhs:
 ; GFX9:       ; %bb.0:
 ; GFX9-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX9-NEXT:    v_pk_mul_f16 v0, v0, v4 neg_lo:[1,1] neg_hi:[1,1]
-; GFX9-NEXT:    v_pk_mul_f16 v1, v1, v5 neg_lo:[1,1] neg_hi:[1,1]
-; GFX9-NEXT:    v_pk_mul_f16 v2, v2, v6 neg_lo:[1,1] neg_hi:[1,1]
-; GFX9-NEXT:    v_pk_mul_f16 v3, v3, v7 neg_lo:[1,1] neg_hi:[1,1]
+; GFX9-NEXT:    v_pk_mul_f16 v0, v0, v4
+; GFX9-NEXT:    v_pk_mul_f16 v1, v1, v5
+; GFX9-NEXT:    v_pk_mul_f16 v2, v2, v6
+; GFX9-NEXT:    v_pk_mul_f16 v3, v3, v7
 ; GFX9-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX8-LABEL: v_fmul_v8f16_fneg_lhs_fneg_rhs:
 ; GFX8:       ; %bb.0:
 ; GFX8-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
-; GFX8-NEXT:    s_mov_b32 s4, 0x80008000
-; GFX8-NEXT:    v_xor_b32_e32 v0, s4, v0
-; GFX8-NEXT:    v_xor_b32_e32 v1, s4, v1
-; GFX8-NEXT:    v_xor_b32_e32 v2, s4, v2
-; GFX8-NEXT:    v_xor_b32_e32 v3, s4, v3
-; GFX8-NEXT:    v_xor_b32_e32 v4, s4, v4
-; GFX8-NEXT:    v_xor_b32_e32 v5, s4, v5
-; GFX8-NEXT:    v_xor_b32_e32 v6, s4, v6
-; GFX8-NEXT:    v_xor_b32_e32 v7, s4, v7
 ; GFX8-NEXT:    v_mul_f16_e32 v8, v0, v4
 ; GFX8-NEXT:    v_mul_f16_sdwa v0, v0, v4 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mul_f16_e32 v4, v1, v5
 ; GFX8-NEXT:    v_mul_f16_sdwa v1, v1, v5 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mul_f16_e32 v5, v2, v6
 ; GFX8-NEXT:    v_mul_f16_sdwa v2, v2, v6 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mul_f16_e32 v6, v3, v7
 ; GFX8-NEXT:    v_mul_f16_sdwa v3, v3, v7 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_1 src1_sel:WORD_1
 ; GFX8-NEXT:    v_mov_b32_e32 v7, 16
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v0, v7, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_mov_b32_e32 v7, 16
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v1, v7, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v2, v7, v2 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_lshlrev_b32_sdwa v3, v7, v3 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:DWORD src1_sel:WORD_0
 ; GFX8-NEXT:    v_or_b32_sdwa v0, v8, v0 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    v_or_b32_sdwa v1, v4, v1 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    v_or_b32_sdwa v2, v5, v2 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    v_or_b32_sdwa v3, v6, v3 dst_sel:DWORD dst_unused:UNUSED_PAD src0_sel:WORD_0 src1_sel:DWORD
 ; GFX8-NEXT:    s_setpc_b64 s[30:31]
 ;
 ; GFX10-LABEL: v_fmul_v8f16_fneg_lhs_fneg_rhs:
 ; GFX10:       ; %bb.0:
 ; GFX10-NEXT:    s_waitcnt vmcnt(0) expcnt(0) lgkmcnt(0)
 ; GFX10-NEXT:    s_waitcnt_vscnt null, 0x0
-; GFX10-NEXT:    v_pk_mul_f16 v0, v0, v4 neg_lo:[1,1] neg_hi:[1,1]
-; GFX10-NEXT:    v_pk_mul_f16 v1, v1, v5 neg_lo:[1,1] neg_hi:[1,1]
-; GFX10-NEXT:    v_pk_mul_f16 v2, v2, v6 neg_lo:[1,1] neg_hi:[1,1]
-; GFX10-NEXT:    v_pk_mul_f16 v3, v3, v7 neg_lo:[1,1] neg_hi:[1,1]
+; GFX10-NEXT:    v_pk_mul_f16 v0, v0, v4
+; GFX10-NEXT:    v_pk_mul_f16 v1, v1, v5
+; GFX10-NEXT:    v_pk_mul_f16 v2, v2, v6
+; GFX10-NEXT:    v_pk_mul_f16 v3, v3, v7
 ; GFX10-NEXT:    s_setpc_b64 s[30:31]
   %neg.a = fneg <8 x half> %a
   %neg.b = fneg <8 x half> %b
   %mul = fmul <8 x half> %neg.a, %neg.b
   ret <8 x half> %mul
 }