diff --git a/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h b/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
--- a/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
+++ b/llvm/include/llvm/CodeGen/GlobalISel/CombinerHelper.h
@@ -696,6 +696,9 @@
   ///           (fma fneg(x), fneg(y), z) -> (fma x, y, z)
   bool matchRedundantNegOperands(MachineInstr &MI, BuildFnTy &MatchInfo);
 
+  bool matchFsubToFneg(MachineInstr &MI, Register &MatchInfo);
+  void applyFsubToFneg(MachineInstr &MI, Register &MatchInfo);
+
   bool canCombineFMadOrFMA(MachineInstr &MI, bool &AllowFusionGlobally,
                            bool &HasFMAD, bool &Aggressive,
                            bool CanReassociate = false);
diff --git a/llvm/include/llvm/Target/GlobalISel/Combine.td b/llvm/include/llvm/Target/GlobalISel/Combine.td
--- a/llvm/include/llvm/Target/GlobalISel/Combine.td
+++ b/llvm/include/llvm/Target/GlobalISel/Combine.td
@@ -856,6 +856,13 @@
     [{ return Helper.matchRedundantNegOperands(*${root}, ${matchinfo}); }]),
   (apply [{ Helper.applyBuildFnNoErase(*${root}, ${matchinfo}); }])>;
 
+// Transform (fsub +-0.0, X) -> (fneg X)
+def fsub_to_fneg: GICombineRule<
+  (defs root:$root, register_matchinfo:$matchinfo),
+  (match (wip_match_opcode G_FSUB):$root,
+    [{ return Helper.matchFsubToFneg(*${root}, ${matchinfo}); }]),
+  (apply [{ Helper.applyFsubToFneg(*${root}, ${matchinfo}); }])>;
+
 // Transform (fadd x, (fmul y, z)) -> (fma y, z, x)
 //           (fadd x, (fmul y, z)) -> (fmad y, z, x)
 // Transform (fadd (fmul x, y), z) -> (fma x, y, z)
@@ -1056,7 +1063,8 @@
     form_bitfield_extract, constant_fold, fabs_fneg_fold,
     intdiv_combines, mulh_combines, redundant_neg_operands,
     and_or_disjoint_mask, fma_combines, fold_binop_into_select,
-    sub_add_reg, select_to_minmax, redundant_binop_in_equality]>;
+    sub_add_reg, select_to_minmax, redundant_binop_in_equality,
+    fsub_to_fneg]>;
 
 // 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
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -5190,6 +5190,38 @@
   return true;
 }
 
+bool CombinerHelper::matchFsubToFneg(MachineInstr &MI, Register &MatchInfo) {
+  assert(MI.getOpcode() == TargetOpcode::G_FSUB);
+
+  Register LHS = MI.getOperand(1).getReg();
+  MatchInfo = MI.getOperand(2).getReg();
+  LLT Ty = MRI.getType(MI.getOperand(0).getReg());
+
+  const auto LHSCst = Ty.isVector()
+                          ? getFConstantSplat(LHS, MRI, /* allowUndef */ true)
+                          : getFConstantVRegValWithLookThrough(LHS, MRI);
+  if (!LHSCst)
+    return false;
+
+  // -0.0 is always allowed
+  if (LHSCst->Value.isNegZero())
+    return true;
+
+  // +0.0 is only allowed if nsz is set.
+  if (LHSCst->Value.isPosZero())
+    return MI.getFlag(MachineInstr::FmNsz);
+
+  return false;
+}
+
+void CombinerHelper::applyFsubToFneg(MachineInstr &MI, Register &MatchInfo) {
+  Builder.setInstrAndDebugLoc(MI);
+  Register Dst = MI.getOperand(0).getReg();
+  Builder.buildFNeg(
+      Dst, Builder.buildFCanonicalize(MRI.getType(Dst), MatchInfo).getReg(0));
+  eraseInst(MI);
+}
+
 /// Checks if \p MI is TargetOpcode::G_FMUL and contractable either
 /// due to global flags or MachineInstr flags.
 static bool isContractableFMul(MachineInstr &MI, bool AllowFusionGlobally) {
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-fsub-fneg.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-fsub-fneg.mir
new file mode 100644
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/combine-fsub-fneg.mir
@@ -0,0 +1,387 @@
+# 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_f16_poszero_nsz
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0
+
+    ; CHECK-LABEL: name: test_f16_poszero_nsz
+    ; CHECK: liveins: $vgpr0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: %input:_(s16) = G_TRUNC [[COPY]](s32)
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(s16) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(s16) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: %res:_(s32) = G_ANYEXT [[FCANONICALIZE]](s16)
+    ; CHECK-NEXT: $vgpr0 = COPY %res(s32)
+    %0:_(s32) = COPY $vgpr0
+    %input:_(s16) = G_TRUNC %0
+    %cst:_(s16) = G_FCONSTANT half 0.0
+    %sub:_(s16) = nsz G_FSUB %cst, %input
+    %res:_(s32) = G_ANYEXT %sub
+    $vgpr0 = COPY %res
+...
+
+---
+name:            test_f16_poszero_nonsz_nofold
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0
+
+    ; CHECK-LABEL: name: test_f16_poszero_nonsz_nofold
+    ; CHECK: liveins: $vgpr0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: %input:_(s16) = G_TRUNC [[COPY]](s32)
+    ; CHECK-NEXT: %cst:_(s16) = G_FCONSTANT half 0xH0000
+    ; CHECK-NEXT: %sub:_(s16) = G_FSUB %cst, %input
+    ; CHECK-NEXT: %res:_(s32) = G_ANYEXT %sub(s16)
+    ; CHECK-NEXT: $vgpr0 = COPY %res(s32)
+    %0:_(s32) = COPY $vgpr0
+    %input:_(s16) = G_TRUNC %0
+    %cst:_(s16) = G_FCONSTANT half 0.0
+    %sub:_(s16) = G_FSUB %cst, %input
+    %res:_(s32) = G_ANYEXT %sub
+    $vgpr0 = COPY %res
+...
+
+---
+name:            test_f16_negzero
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0
+
+    ; CHECK-LABEL: name: test_f16_negzero
+    ; CHECK: liveins: $vgpr0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: %input:_(s16) = G_TRUNC [[COPY]](s32)
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(s16) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(s16) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: %res:_(s32) = G_ANYEXT [[FCANONICALIZE]](s16)
+    ; CHECK-NEXT: $vgpr0 = COPY %res(s32)
+    %0:_(s32) = COPY $vgpr0
+    %input:_(s16) = G_TRUNC %0
+    %cst:_(s16) = G_FCONSTANT half -0.0
+    %sub:_(s16) = G_FSUB %cst, %input
+    %res:_(s32) = G_ANYEXT %sub
+    $vgpr0 = COPY %res
+...
+
+---
+name:            test_f32_poszero_nsz
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0
+
+    ; CHECK-LABEL: name: test_f32_poszero_nsz
+    ; CHECK: liveins: $vgpr0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(s32) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(s32) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FCANONICALIZE]](s32)
+    %input:_(s32) = COPY $vgpr0
+    %cst:_(s32) = G_FCONSTANT float 0.0
+    %sub:_(s32) = nsz G_FSUB %cst, %input
+    $vgpr0 = COPY %sub
+...
+
+---
+name:            test_f32_poszero_nonsz_nofold
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0
+
+    ; CHECK-LABEL: name: test_f32_poszero_nonsz_nofold
+    ; CHECK: liveins: $vgpr0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: %cst:_(s32) = G_FCONSTANT float 0.000000e+00
+    ; CHECK-NEXT: %sub:_(s32) = G_FSUB %cst, %input
+    ; CHECK-NEXT: $vgpr0 = COPY %sub(s32)
+    %input:_(s32) = COPY $vgpr0
+    %cst:_(s32) = G_FCONSTANT float 0.0
+    %sub:_(s32) = G_FSUB %cst, %input
+    $vgpr0 = COPY %sub
+...
+
+---
+name:            test_f32_negzero
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0
+
+    ; CHECK-LABEL: name: test_f32_negzero
+    ; CHECK: liveins: $vgpr0
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(s32) = COPY $vgpr0
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(s32) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(s32) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0 = COPY [[FCANONICALIZE]](s32)
+    %input:_(s32) = COPY $vgpr0
+    %cst:_(s32) = G_FCONSTANT float -0.0
+    %sub:_(s32) = G_FSUB %cst, %input
+    $vgpr0 = COPY %sub
+...
+
+---
+name:            test_f64_poszero_nsz
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1
+
+    ; CHECK-LABEL: name: test_f64_poszero_nsz
+    ; CHECK: liveins: $vgpr0_vgpr1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(s64) = COPY $vgpr0_vgpr1
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(s64) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(s64) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1 = COPY [[FCANONICALIZE]](s64)
+    %input:_(s64) = COPY $vgpr0_vgpr1
+    %cst:_(s64) = G_FCONSTANT double 0.0
+    %sub:_(s64) = nsz G_FSUB %cst, %input
+    $vgpr0_vgpr1 = COPY %sub
+...
+
+---
+name:            test_f64_poszero_nonsz_nofold
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1
+
+    ; CHECK-LABEL: name: test_f64_poszero_nonsz_nofold
+    ; CHECK: liveins: $vgpr0_vgpr1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(s64) = COPY $vgpr0_vgpr1
+    ; CHECK-NEXT: %cst:_(s64) = G_FCONSTANT double 0.000000e+00
+    ; CHECK-NEXT: %sub:_(s64) = G_FSUB %cst, %input
+    ; CHECK-NEXT: $vgpr0_vgpr1 = COPY %sub(s64)
+    %input:_(s64) = COPY $vgpr0_vgpr1
+    %cst:_(s64) = G_FCONSTANT double 0.0
+    %sub:_(s64) = G_FSUB %cst, %input
+    $vgpr0_vgpr1 = COPY %sub
+...
+
+---
+name:            test_f64_negzero
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1
+
+    ; CHECK-LABEL: name: test_f64_negzero
+    ; CHECK: liveins: $vgpr0_vgpr1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(s64) = COPY $vgpr0_vgpr1
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(s64) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(s64) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1 = COPY [[FCANONICALIZE]](s64)
+    %input:_(s64) = COPY $vgpr0_vgpr1
+    %cst:_(s64) = G_FCONSTANT double -0.0
+    %sub:_(s64) = G_FSUB %cst, %input
+    $vgpr0_vgpr1 = COPY %sub
+...
+
+---
+name:            test_v4f16_poszero_nsz
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1
+
+    ; CHECK-LABEL: name: test_v4f16_poszero_nsz
+    ; CHECK: liveins: $vgpr0_vgpr1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<4 x s16>) = COPY $vgpr0_vgpr1
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(<4 x s16>) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(<4 x s16>) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1 = COPY [[FCANONICALIZE]](<4 x s16>)
+    %input:_(<4 x s16>) = COPY $vgpr0_vgpr1
+    %cst:_(s16) = G_FCONSTANT half 0.0
+    %veccst:_(<4 x s16>) = G_BUILD_VECTOR %cst, %cst, %cst, %cst
+    %sub:_(<4 x s16>) = nsz G_FSUB %veccst, %input
+    $vgpr0_vgpr1 = COPY %sub
+...
+
+---
+name:            test_v4f16_poszero_nonsz_nofold
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1
+
+    ; CHECK-LABEL: name: test_v4f16_poszero_nonsz_nofold
+    ; CHECK: liveins: $vgpr0_vgpr1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<4 x s16>) = COPY $vgpr0_vgpr1
+    ; CHECK-NEXT: %cst:_(s16) = G_FCONSTANT half 0xH0000
+    ; CHECK-NEXT: %veccst:_(<4 x s16>) = G_BUILD_VECTOR %cst(s16), %cst(s16), %cst(s16), %cst(s16)
+    ; CHECK-NEXT: %sub:_(<4 x s16>) = G_FSUB %veccst, %input
+    ; CHECK-NEXT: $vgpr0_vgpr1 = COPY %sub(<4 x s16>)
+    %input:_(<4 x s16>) = COPY $vgpr0_vgpr1
+    %cst:_(s16) = G_FCONSTANT half 0.0
+    %veccst:_(<4 x s16>) = G_BUILD_VECTOR %cst, %cst, %cst, %cst
+    %sub:_(<4 x s16>) = G_FSUB %veccst, %input
+    $vgpr0_vgpr1 = COPY %sub
+...
+
+---
+name:            test_v4f16_negzero
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1
+
+    ; CHECK-LABEL: name: test_v4f16_negzero
+    ; CHECK: liveins: $vgpr0_vgpr1
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<4 x s16>) = COPY $vgpr0_vgpr1
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(<4 x s16>) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(<4 x s16>) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1 = COPY [[FCANONICALIZE]](<4 x s16>)
+    %input:_(<4 x s16>) = COPY $vgpr0_vgpr1
+    %cst:_(s16) = G_FCONSTANT half -0.0
+    %veccst:_(<4 x s16>) = G_BUILD_VECTOR %cst, %cst, %cst, %cst
+    %sub:_(<4 x s16>) = G_FSUB %veccst, %input
+    $vgpr0_vgpr1 = COPY %sub
+...
+
+---
+name:            test_v4f32
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+
+    ; CHECK-LABEL: name: test_v4f32
+    ; CHECK: liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<4 x s32>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(<4 x s32>) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(<4 x s32>) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1_vgpr2_vgpr3 = COPY [[FCANONICALIZE]](<4 x s32>)
+    %input:_(<4 x s32>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    %cst:_(s32) = G_FCONSTANT float 0.0
+    %veccst:_(<4 x s32>) = G_BUILD_VECTOR %cst, %cst, %cst, %cst
+    %sub:_(<4 x s32>) = nsz G_FSUB %veccst, %input
+    $vgpr0_vgpr1_vgpr2_vgpr3 = COPY %sub
+...
+
+---
+name:            test_v4f32_negzero
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+
+    ; CHECK-LABEL: name: test_v4f32_negzero
+    ; CHECK: liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<4 x s32>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(<4 x s32>) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(<4 x s32>) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1_vgpr2_vgpr3 = COPY [[FCANONICALIZE]](<4 x s32>)
+    %input:_(<4 x s32>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    %cst:_(s32) = G_FCONSTANT float -0.0
+    %veccst:_(<4 x s32>) = G_BUILD_VECTOR %cst, %cst, %cst, %cst
+    %sub:_(<4 x s32>) = G_FSUB %veccst, %input
+    $vgpr0_vgpr1_vgpr2_vgpr3 = COPY %sub
+...
+
+---
+name:            test_v4f32_negzero_undef_elt
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+
+    ; CHECK-LABEL: name: test_v4f32_negzero_undef_elt
+    ; CHECK: liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<4 x s32>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(<4 x s32>) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(<4 x s32>) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1_vgpr2_vgpr3 = COPY [[FCANONICALIZE]](<4 x s32>)
+    %input:_(<4 x s32>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    %cst:_(s32) = G_FCONSTANT float -0.0
+    %undef:_(s32) = G_IMPLICIT_DEF
+    %veccst:_(<4 x s32>) = G_BUILD_VECTOR %cst, %undef, %cst, %cst
+    %sub:_(<4 x s32>) = G_FSUB %veccst, %input
+    $vgpr0_vgpr1_vgpr2_vgpr3 = COPY %sub
+...
+
+---
+name:            test_v4f32_poszero_undef_elt
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+
+    ; CHECK-LABEL: name: test_v4f32_poszero_undef_elt
+    ; CHECK: liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<4 x s32>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(<4 x s32>) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(<4 x s32>) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1_vgpr2_vgpr3 = COPY [[FCANONICALIZE]](<4 x s32>)
+    %input:_(<4 x s32>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    %cst:_(s32) = G_FCONSTANT float 0.0
+    %undef:_(s32) = G_IMPLICIT_DEF
+    %veccst:_(<4 x s32>) = G_BUILD_VECTOR %cst, %undef, %cst, %cst
+    %sub:_(<4 x s32>) = nsz G_FSUB %veccst, %input
+    $vgpr0_vgpr1_vgpr2_vgpr3 = COPY %sub
+...
+
+---
+name:            test_v2f64
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+
+    ; CHECK-LABEL: name: test_v2f64
+    ; CHECK: liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<2 x s64>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(<2 x s64>) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(<2 x s64>) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1_vgpr2_vgpr3 = COPY [[FCANONICALIZE]](<2 x s64>)
+    %input:_(<2 x s64>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    %cst:_(s64) = G_FCONSTANT double 0.0
+    %veccst:_(<2 x s64>) = G_BUILD_VECTOR %cst, %cst
+    %sub:_(<2 x s64>) = nsz G_FSUB %veccst, %input
+    $vgpr0_vgpr1_vgpr2_vgpr3 = COPY %sub
+...
+
+---
+name:            test_v2f64_negzero
+tracksRegLiveness: true
+body:             |
+  bb.0:
+    liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+
+    ; CHECK-LABEL: name: test_v2f64_negzero
+    ; CHECK: liveins: $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: {{  $}}
+    ; CHECK-NEXT: %input:_(<2 x s64>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    ; CHECK-NEXT: [[FNEG:%[0-9]+]]:_(<2 x s64>) = G_FNEG %input
+    ; CHECK-NEXT: [[FCANONICALIZE:%[0-9]+]]:_(<2 x s64>) = G_FCANONICALIZE [[FNEG]]
+    ; CHECK-NEXT: $vgpr0_vgpr1_vgpr2_vgpr3 = COPY [[FCANONICALIZE]](<2 x s64>)
+    %input:_(<2 x s64>) = COPY $vgpr0_vgpr1_vgpr2_vgpr3
+    %cst:_(s64) = G_FCONSTANT double -0.0
+    %veccst:_(<2 x s64>) = G_BUILD_VECTOR %cst, %cst
+    %sub:_(<2 x s64>) = G_FSUB %veccst, %input
+    $vgpr0_vgpr1_vgpr2_vgpr3 = COPY %sub
+...
+
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/fmed3.ll b/llvm/test/CodeGen/AMDGPU/GlobalISel/fmed3.ll
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/fmed3.ll
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/fmed3.ll
@@ -23,7 +23,7 @@
 ; SI-NEXT:    s_mov_b64 s[8:9], s[6:7]
 ; SI-NEXT:    buffer_load_dword v4, v[0:1], s[8:11], 0 addr64 glc
 ; SI-NEXT:    s_waitcnt vmcnt(0)
-; SI-NEXT:    v_sub_f32_e32 v2, 0x80000000, v2
+; SI-NEXT:    v_mul_f32_e32 v2, -1.0, v2
 ; SI-NEXT:    v_med3_f32 v2, v2, v3, v4
 ; SI-NEXT:    s_mov_b64 s[2:3], s[10:11]
 ; SI-NEXT:    buffer_store_dword v2, v[0:1], s[0:3], 0 addr64
@@ -56,7 +56,7 @@
 ; VI-NEXT:    v_mov_b32_e32 v1, s1
 ; VI-NEXT:    v_add_u32_e32 v0, vcc, v0, v6
 ; VI-NEXT:    v_addc_u32_e32 v1, vcc, 0, v1, vcc
-; VI-NEXT:    v_sub_f32_e32 v4, 0x80000000, v7
+; VI-NEXT:    v_mul_f32_e32 v4, -1.0, v7
 ; VI-NEXT:    v_med3_f32 v2, v4, v2, v3
 ; VI-NEXT:    flat_store_dword v[0:1], v2
 ; VI-NEXT:    s_endpgm
@@ -72,7 +72,7 @@
 ; GFX9-NEXT:    s_waitcnt vmcnt(0)
 ; GFX9-NEXT:    global_load_dword v3, v0, s[6:7] glc
 ; GFX9-NEXT:    s_waitcnt vmcnt(0)
-; GFX9-NEXT:    v_sub_f32_e32 v1, 0x80000000, v1
+; GFX9-NEXT:    v_max_f32_e64 v1, -v1, -v1
 ; GFX9-NEXT:    v_med3_f32 v1, v1, v2, v3
 ; GFX9-NEXT:    global_store_dword v0, v1, s[0:1]
 ; GFX9-NEXT:    s_endpgm
@@ -88,7 +88,7 @@
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
 ; GFX10-NEXT:    global_load_dword v3, v0, s[6:7] glc dlc
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
-; GFX10-NEXT:    v_sub_f32_e32 v1, 0x80000000, v1
+; GFX10-NEXT:    v_max_f32_e64 v1, -v1, -v1
 ; GFX10-NEXT:    v_med3_f32 v1, v1, v2, v3
 ; GFX10-NEXT:    global_store_dword v0, v1, s[0:1]
 ; GFX10-NEXT:    s_endpgm
@@ -104,7 +104,7 @@
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
 ; GFX11-NEXT:    global_load_b32 v3, v0, s[6:7] glc dlc
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
-; GFX11-NEXT:    v_sub_f32_e32 v1, 0x80000000, v1
+; GFX11-NEXT:    v_max_f32_e64 v1, -v1, -v1
 ; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
 ; GFX11-NEXT:    v_med3_f32 v1, v1, v2, v3
 ; GFX11-NEXT:    global_store_b32 v0, v1, s[0:1]
@@ -145,7 +145,7 @@
 ; SI-NEXT:    s_mov_b64 s[8:9], s[6:7]
 ; SI-NEXT:    buffer_load_dword v4, v[0:1], s[8:11], 0 addr64 glc
 ; SI-NEXT:    s_waitcnt vmcnt(0)
-; SI-NEXT:    v_sub_f32_e32 v2, 0x80000000, v2
+; SI-NEXT:    v_mul_f32_e32 v2, -1.0, v2
 ; SI-NEXT:    v_mul_f32_e32 v3, 1.0, v3
 ; SI-NEXT:    v_min_f32_e32 v5, v2, v3
 ; SI-NEXT:    v_max_f32_e32 v2, v2, v3
@@ -183,7 +183,7 @@
 ; VI-NEXT:    v_mov_b32_e32 v1, s1
 ; VI-NEXT:    v_add_u32_e32 v0, vcc, v0, v6
 ; VI-NEXT:    v_addc_u32_e32 v1, vcc, 0, v1, vcc
-; VI-NEXT:    v_sub_f32_e32 v4, 0x80000000, v7
+; VI-NEXT:    v_mul_f32_e32 v4, -1.0, v7
 ; VI-NEXT:    v_mul_f32_e32 v2, 1.0, v2
 ; VI-NEXT:    v_min_f32_e32 v5, v4, v2
 ; VI-NEXT:    v_max_f32_e32 v2, v4, v2
@@ -204,7 +204,7 @@
 ; GFX9-NEXT:    s_waitcnt vmcnt(0)
 ; GFX9-NEXT:    global_load_dword v3, v0, s[6:7] glc
 ; GFX9-NEXT:    s_waitcnt vmcnt(0)
-; GFX9-NEXT:    v_sub_f32_e32 v1, 0x80000000, v1
+; GFX9-NEXT:    v_max_f32_e64 v1, -v1, -v1
 ; GFX9-NEXT:    v_max_f32_e32 v2, v2, v2
 ; GFX9-NEXT:    v_min_f32_e32 v4, v1, v2
 ; GFX9-NEXT:    v_max_f32_e32 v1, v1, v2
@@ -225,7 +225,7 @@
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
 ; GFX10-NEXT:    global_load_dword v3, v0, s[6:7] glc dlc
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
-; GFX10-NEXT:    v_sub_f32_e32 v1, 0x80000000, v1
+; GFX10-NEXT:    v_max_f32_e64 v1, -v1, -v1
 ; GFX10-NEXT:    v_max_f32_e32 v2, v2, v2
 ; GFX10-NEXT:    v_max_f32_e32 v3, v3, v3
 ; GFX10-NEXT:    v_max_f32_e32 v4, v1, v2
@@ -246,7 +246,8 @@
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
 ; GFX11-NEXT:    global_load_b32 v3, v0, s[6:7] glc dlc
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
-; GFX11-NEXT:    v_dual_sub_f32 v1, 0x80000000, v1 :: v_dual_max_f32 v2, v2, v2
+; GFX11-NEXT:    v_max_f32_e64 v1, -v1, -v1
+; GFX11-NEXT:    v_max_f32_e32 v2, v2, v2
 ; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1) | instskip(SKIP_1) | instid1(VALU_DEP_1)
 ; GFX11-NEXT:    v_min_f32_e32 v4, v1, v2
 ; GFX11-NEXT:    v_dual_max_f32 v1, v1, v2 :: v_dual_max_f32 v2, v3, v3
@@ -289,9 +290,8 @@
 ; SI-NEXT:    s_mov_b64 s[8:9], s[6:7]
 ; SI-NEXT:    buffer_load_dword v4, v[0:1], s[8:11], 0 addr64 glc
 ; SI-NEXT:    s_waitcnt vmcnt(0)
-; SI-NEXT:    s_mov_b32 s2, 0x80000000
-; SI-NEXT:    v_sub_f32_e32 v2, 0x80000000, v2
-; SI-NEXT:    v_sub_f32_e64 v4, s2, |v4|
+; SI-NEXT:    v_mul_f32_e32 v2, -1.0, v2
+; SI-NEXT:    v_mul_f32_e64 v4, -1.0, |v4|
 ; SI-NEXT:    v_med3_f32 v2, v2, |v3|, v4
 ; SI-NEXT:    s_mov_b64 s[2:3], s[10:11]
 ; SI-NEXT:    buffer_store_dword v2, v[0:1], s[0:3], 0 addr64
@@ -320,13 +320,12 @@
 ; VI-NEXT:    s_waitcnt vmcnt(0)
 ; VI-NEXT:    flat_load_dword v3, v[4:5] glc
 ; VI-NEXT:    s_waitcnt vmcnt(0)
-; VI-NEXT:    s_mov_b32 s2, 0x80000000
 ; VI-NEXT:    v_mov_b32_e32 v0, s0
 ; VI-NEXT:    v_mov_b32_e32 v1, s1
 ; VI-NEXT:    v_add_u32_e32 v0, vcc, v0, v6
 ; VI-NEXT:    v_addc_u32_e32 v1, vcc, 0, v1, vcc
-; VI-NEXT:    v_sub_f32_e32 v4, 0x80000000, v7
-; VI-NEXT:    v_sub_f32_e64 v3, s2, |v3|
+; VI-NEXT:    v_mul_f32_e32 v4, -1.0, v7
+; VI-NEXT:    v_mul_f32_e64 v3, -1.0, |v3|
 ; VI-NEXT:    v_med3_f32 v2, v4, |v2|, v3
 ; VI-NEXT:    flat_store_dword v[0:1], v2
 ; VI-NEXT:    s_endpgm
@@ -342,9 +341,8 @@
 ; GFX9-NEXT:    s_waitcnt vmcnt(0)
 ; GFX9-NEXT:    global_load_dword v3, v0, s[6:7] glc
 ; GFX9-NEXT:    s_waitcnt vmcnt(0)
-; GFX9-NEXT:    s_mov_b32 s2, 0x80000000
-; GFX9-NEXT:    v_sub_f32_e32 v1, 0x80000000, v1
-; GFX9-NEXT:    v_sub_f32_e64 v3, s2, |v3|
+; GFX9-NEXT:    v_max_f32_e64 v1, -v1, -v1
+; GFX9-NEXT:    v_max_f32_e64 v3, -|v3|, -|v3|
 ; GFX9-NEXT:    v_med3_f32 v1, v1, |v2|, v3
 ; GFX9-NEXT:    global_store_dword v0, v1, s[0:1]
 ; GFX9-NEXT:    s_endpgm
@@ -360,8 +358,8 @@
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
 ; GFX10-NEXT:    global_load_dword v3, v0, s[6:7] glc dlc
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
-; GFX10-NEXT:    v_sub_f32_e32 v1, 0x80000000, v1
-; GFX10-NEXT:    v_sub_f32_e64 v3, 0x80000000, |v3|
+; GFX10-NEXT:    v_max_f32_e64 v1, -v1, -v1
+; GFX10-NEXT:    v_max_f32_e64 v3, -|v3|, -|v3|
 ; GFX10-NEXT:    v_med3_f32 v1, v1, |v2|, v3
 ; GFX10-NEXT:    global_store_dword v0, v1, s[0:1]
 ; GFX10-NEXT:    s_endpgm
@@ -377,8 +375,8 @@
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
 ; GFX11-NEXT:    global_load_b32 v3, v0, s[6:7] glc dlc
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
-; GFX11-NEXT:    v_sub_f32_e32 v1, 0x80000000, v1
-; GFX11-NEXT:    v_sub_f32_e64 v3, 0x80000000, |v3|
+; GFX11-NEXT:    v_max_f32_e64 v1, -v1, -v1
+; GFX11-NEXT:    v_max_f32_e64 v3, -|v3|, -|v3|
 ; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
 ; GFX11-NEXT:    v_med3_f32 v1, v1, |v2|, v3
 ; GFX11-NEXT:    global_store_b32 v0, v1, s[0:1]
@@ -425,10 +423,9 @@
 ; SI-NEXT:    s_mov_b64 s[8:9], s[6:7]
 ; SI-NEXT:    buffer_load_dword v4, v[0:1], s[8:11], 0 addr64 glc
 ; SI-NEXT:    s_waitcnt vmcnt(0)
-; SI-NEXT:    s_mov_b32 s2, 0x80000000
-; SI-NEXT:    v_sub_f32_e64 v2, s2, |v2|
-; SI-NEXT:    v_sub_f32_e64 v3, s2, |v3|
-; SI-NEXT:    v_sub_f32_e64 v4, s2, |v4|
+; SI-NEXT:    v_mul_f32_e64 v2, -1.0, |v2|
+; SI-NEXT:    v_mul_f32_e64 v3, -1.0, |v3|
+; SI-NEXT:    v_mul_f32_e64 v4, -1.0, |v4|
 ; SI-NEXT:    v_med3_f32 v2, v2, v3, v4
 ; SI-NEXT:    s_mov_b64 s[2:3], s[10:11]
 ; SI-NEXT:    buffer_store_dword v2, v[0:1], s[0:3], 0 addr64
@@ -457,14 +454,13 @@
 ; VI-NEXT:    s_waitcnt vmcnt(0)
 ; VI-NEXT:    flat_load_dword v3, v[4:5] glc
 ; VI-NEXT:    s_waitcnt vmcnt(0)
-; VI-NEXT:    s_mov_b32 s2, 0x80000000
 ; VI-NEXT:    v_mov_b32_e32 v0, s0
 ; VI-NEXT:    v_mov_b32_e32 v1, s1
 ; VI-NEXT:    v_add_u32_e32 v0, vcc, v0, v6
 ; VI-NEXT:    v_addc_u32_e32 v1, vcc, 0, v1, vcc
-; VI-NEXT:    v_sub_f32_e64 v4, s2, |v7|
-; VI-NEXT:    v_sub_f32_e64 v2, s2, |v2|
-; VI-NEXT:    v_sub_f32_e64 v3, s2, |v3|
+; VI-NEXT:    v_mul_f32_e64 v4, -1.0, |v7|
+; VI-NEXT:    v_mul_f32_e64 v2, -1.0, |v2|
+; VI-NEXT:    v_mul_f32_e64 v3, -1.0, |v3|
 ; VI-NEXT:    v_med3_f32 v2, v4, v2, v3
 ; VI-NEXT:    flat_store_dword v[0:1], v2
 ; VI-NEXT:    s_endpgm
@@ -480,10 +476,9 @@
 ; GFX9-NEXT:    s_waitcnt vmcnt(0)
 ; GFX9-NEXT:    global_load_dword v3, v0, s[6:7] glc
 ; GFX9-NEXT:    s_waitcnt vmcnt(0)
-; GFX9-NEXT:    s_mov_b32 s2, 0x80000000
-; GFX9-NEXT:    v_sub_f32_e64 v1, s2, |v1|
-; GFX9-NEXT:    v_sub_f32_e64 v2, s2, |v2|
-; GFX9-NEXT:    v_sub_f32_e64 v3, s2, |v3|
+; GFX9-NEXT:    v_max_f32_e64 v1, -|v1|, -|v1|
+; GFX9-NEXT:    v_max_f32_e64 v2, -|v2|, -|v2|
+; GFX9-NEXT:    v_max_f32_e64 v3, -|v3|, -|v3|
 ; GFX9-NEXT:    v_med3_f32 v1, v1, v2, v3
 ; GFX9-NEXT:    global_store_dword v0, v1, s[0:1]
 ; GFX9-NEXT:    s_endpgm
@@ -499,9 +494,9 @@
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
 ; GFX10-NEXT:    global_load_dword v3, v0, s[6:7] glc dlc
 ; GFX10-NEXT:    s_waitcnt vmcnt(0)
-; GFX10-NEXT:    v_sub_f32_e64 v1, 0x80000000, |v1|
-; GFX10-NEXT:    v_sub_f32_e64 v2, 0x80000000, |v2|
-; GFX10-NEXT:    v_sub_f32_e64 v3, 0x80000000, |v3|
+; GFX10-NEXT:    v_max_f32_e64 v1, -|v1|, -|v1|
+; GFX10-NEXT:    v_max_f32_e64 v2, -|v2|, -|v2|
+; GFX10-NEXT:    v_max_f32_e64 v3, -|v3|, -|v3|
 ; GFX10-NEXT:    v_med3_f32 v1, v1, v2, v3
 ; GFX10-NEXT:    global_store_dword v0, v1, s[0:1]
 ; GFX10-NEXT:    s_endpgm
@@ -517,9 +512,9 @@
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
 ; GFX11-NEXT:    global_load_b32 v3, v0, s[6:7] glc dlc
 ; GFX11-NEXT:    s_waitcnt vmcnt(0)
-; GFX11-NEXT:    v_sub_f32_e64 v1, 0x80000000, |v1|
-; GFX11-NEXT:    v_sub_f32_e64 v2, 0x80000000, |v2|
-; GFX11-NEXT:    v_sub_f32_e64 v3, 0x80000000, |v3|
+; GFX11-NEXT:    v_max_f32_e64 v1, -|v1|, -|v1|
+; GFX11-NEXT:    v_max_f32_e64 v2, -|v2|, -|v2|
+; GFX11-NEXT:    v_max_f32_e64 v3, -|v3|, -|v3|
 ; GFX11-NEXT:    s_delay_alu instid0(VALU_DEP_1)
 ; GFX11-NEXT:    v_med3_f32 v1, v1, v2, v3
 ; GFX11-NEXT:    global_store_b32 v0, v1, s[0:1]
diff --git a/llvm/test/CodeGen/AMDGPU/v_pack.ll b/llvm/test/CodeGen/AMDGPU/v_pack.ll
--- a/llvm/test/CodeGen/AMDGPU/v_pack.ll
+++ b/llvm/test/CodeGen/AMDGPU/v_pack.ll
@@ -223,9 +223,7 @@
 ; GISEL-NEXT:    s_waitcnt vmcnt(0)
 ; GISEL-NEXT:    v_add_f16_e32 v0, 2.0, v1
 ; GISEL-NEXT:    v_add_f16_e32 v1, 2.0, v2
-; GISEL-NEXT:    v_sub_f16_e32 v0, 0x8000, v0
-; GISEL-NEXT:    v_sub_f16_e32 v1, 0x8000, v1
-; GISEL-NEXT:    v_pack_b32_f16 v0, v0, v1
+; GISEL-NEXT:    v_pack_b32_f16 v0, -v0, -v1
 ; GISEL-NEXT:    ;;#ASMSTART
 ; GISEL-NEXT:    ; use v0
 ; GISEL-NEXT:    ;;#ASMEND