diff --git a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
--- a/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
+++ b/llvm/lib/Target/AMDGPU/SIISelLowering.cpp
@@ -4118,6 +4118,7 @@
     unsigned Opc = (MI.getOpcode() == AMDGPU::S_ADD_CO_PSEUDO)
                        ? AMDGPU::S_ADDC_U32
                        : AMDGPU::S_SUBB_U32;
+
     if (Src0.isReg() && TRI->isVectorRegister(MRI, Src0.getReg())) {
       Register RegOp0 = MRI.createVirtualRegister(&AMDGPU::SReg_32RegClass);
       BuildMI(*BB, MII, DL, TII->get(AMDGPU::V_READFIRSTLANE_B32), RegOp0)
@@ -4138,7 +4139,10 @@
     }
 
     const TargetRegisterClass *Src2RC = MRI.getRegClass(Src2.getReg());
-    if (TRI->getRegSizeInBits(*Src2RC) == 64) {
+    unsigned WaveSize = TRI->getRegSizeInBits(*Src2RC);
+    assert(WaveSize == 64 || WaveSize == 32);
+
+    if (WaveSize == 64) {
       if (ST.hasScalarCompareEq64()) {
         BuildMI(*BB, MII, DL, TII->get(AMDGPU::S_CMP_LG_U64))
             .addReg(Src2.getReg())
@@ -4168,8 +4172,13 @@
 
     BuildMI(*BB, MII, DL, TII->get(Opc), Dest.getReg()).add(Src0).add(Src1);
 
-    BuildMI(*BB, MII, DL, TII->get(AMDGPU::COPY), CarryDest.getReg())
-      .addReg(AMDGPU::SCC);
+    unsigned SelOpc =
+        (WaveSize == 64) ? AMDGPU::S_CSELECT_B64 : AMDGPU::S_CSELECT_B32;
+
+    BuildMI(*BB, MII, DL, TII->get(SelOpc), CarryDest.getReg())
+        .addImm(-1)
+        .addImm(0);
+
     MI.eraseFromParent();
     return BB;
   }
diff --git a/llvm/test/CodeGen/AMDGPU/expand-scalar-carry-out-select-user.ll b/llvm/test/CodeGen/AMDGPU/expand-scalar-carry-out-select-user.ll
--- a/llvm/test/CodeGen/AMDGPU/expand-scalar-carry-out-select-user.ll
+++ b/llvm/test/CodeGen/AMDGPU/expand-scalar-carry-out-select-user.ll
@@ -14,7 +14,7 @@
 ; GFX7-NEXT:    s_or_b32 s4, s4, s5
 ; GFX7-NEXT:    s_cmp_lg_u32 s4, 0
 ; GFX7-NEXT:    s_addc_u32 s4, s6, 0
-; GFX7-NEXT:    s_cselect_b64 vcc, 1, 0
+; GFX7-NEXT:    s_cselect_b64 vcc, -1, 0
 ; GFX7-NEXT:    v_mov_b32_e32 v1, s4
 ; GFX7-NEXT:    s_cmp_gt_u32 s6, 31
 ; GFX7-NEXT:    v_cndmask_b32_e32 v1, 0, v1, vcc
@@ -31,7 +31,7 @@
 ; GFX9-NEXT:    v_add_co_u32_e64 v0, s[4:5], s6, s6
 ; GFX9-NEXT:    s_cmp_lg_u64 s[4:5], 0
 ; GFX9-NEXT:    s_addc_u32 s4, s6, 0
-; GFX9-NEXT:    s_cselect_b64 vcc, 1, 0
+; GFX9-NEXT:    s_cselect_b64 vcc, -1, 0
 ; GFX9-NEXT:    v_mov_b32_e32 v1, s4
 ; GFX9-NEXT:    s_cmp_gt_u32 s6, 31
 ; GFX9-NEXT:    v_cndmask_b32_e32 v1, 0, v1, vcc
@@ -49,7 +49,7 @@
 ; GFX10-NEXT:    v_add_co_u32 v0, s5, s4, s4
 ; GFX10-NEXT:    s_cmpk_lg_u32 s5, 0x0
 ; GFX10-NEXT:    s_addc_u32 s5, s4, 0
-; GFX10-NEXT:    s_cselect_b32 s6, 1, 0
+; GFX10-NEXT:    s_cselect_b32 s6, -1, 0
 ; GFX10-NEXT:    s_cmp_gt_u32 s4, 31
 ; GFX10-NEXT:    v_cndmask_b32_e64 v1, 0, s5, s6
 ; GFX10-NEXT:    s_cselect_b32 vcc_lo, -1, 0