Index: llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUInstPrinter.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUInstPrinter.cpp
+++ llvm/lib/Target/AMDGPU/MCTargetDesc/AMDGPUInstPrinter.cpp
@@ -1397,21 +1397,26 @@
   unsigned Vmcnt, Expcnt, Lgkmcnt;
   decodeWaitcnt(ISA, SImm16, Vmcnt, Expcnt, Lgkmcnt);
 
+  bool IsDefaultVmcnt = Vmcnt == getVmcntBitMask(ISA);
+  bool IsDefaultExpcnt = Expcnt == getExpcntBitMask(ISA);
+  bool IsDefaultLgkmcnt = Lgkmcnt == getLgkmcntBitMask(ISA);
+  bool PrintAll = IsDefaultVmcnt && IsDefaultExpcnt && IsDefaultLgkmcnt;
+
   bool NeedSpace = false;
 
-  if (Vmcnt != getVmcntBitMask(ISA)) {
+  if (!IsDefaultVmcnt || PrintAll) {
     O << "vmcnt(" << Vmcnt << ')';
     NeedSpace = true;
   }
 
-  if (Expcnt != getExpcntBitMask(ISA)) {
+  if (!IsDefaultExpcnt || PrintAll) {
     if (NeedSpace)
       O << ' ';
     O << "expcnt(" << Expcnt << ')';
     NeedSpace = true;
   }
 
-  if (Lgkmcnt != getLgkmcntBitMask(ISA)) {
+  if (!IsDefaultLgkmcnt || PrintAll) {
     if (NeedSpace)
       O << ' ';
     O << "lgkmcnt(" << Lgkmcnt << ')';
Index: llvm/test/MC/AMDGPU/sopp.s
===================================================================
--- llvm/test/MC/AMDGPU/sopp.s
+++ llvm/test/MC/AMDGPU/sopp.s
@@ -81,31 +81,31 @@
 // GCN: s_waitcnt vmcnt(9) ; encoding: [0x79,0x0f,0x8c,0xbf]
 
 s_waitcnt vmcnt(15)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 s_waitcnt vmcnt_sat(9)
 // GCN: s_waitcnt vmcnt(9) ; encoding: [0x79,0x0f,0x8c,0xbf]
 
 s_waitcnt vmcnt_sat(15)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 s_waitcnt vmcnt_sat(16)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 s_waitcnt expcnt(2)
 // GCN: s_waitcnt expcnt(2) ; encoding: [0x2f,0x0f,0x8c,0xbf]
 
 s_waitcnt expcnt(7)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 s_waitcnt expcnt_sat(2)
 // GCN: s_waitcnt expcnt(2) ; encoding: [0x2f,0x0f,0x8c,0xbf]
 
 s_waitcnt expcnt_sat(7)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 s_waitcnt expcnt_sat(0xFFFF0000)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 s_waitcnt lgkmcnt(3)
 // GCN: s_waitcnt lgkmcnt(3) ; encoding: [0x7f,0x03,0x8c,0xbf]
@@ -114,7 +114,7 @@
 // GCN: s_waitcnt lgkmcnt(9) ; encoding: [0x7f,0x09,0x8c,0xbf]
 
 s_waitcnt lgkmcnt(15)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 s_waitcnt vmcnt(0), expcnt(0)
 // GCN: s_waitcnt vmcnt(0) expcnt(0) ; encoding: [0x00,0x0f,0x8c,0xbf]
@@ -126,10 +126,10 @@
 // GCN: s_waitcnt lgkmcnt(9) ; encoding: [0x7f,0x09,0x8c,0xbf]
 
 s_waitcnt lgkmcnt_sat(15)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 s_waitcnt lgkmcnt_sat(16)
-// GCN: s_waitcnt ; encoding: [0x7f,0x0f,0x8c,0xbf]
+// GCN: s_waitcnt vmcnt(15) expcnt(7) lgkmcnt(15) ; encoding: [0x7f,0x0f,0x8c,0xbf]
 
 x=1
 s_waitcnt lgkmcnt_sat(x+1)