Index: lib/Target/AMDGPU/SIInstrInfo.td
===================================================================
--- lib/Target/AMDGPU/SIInstrInfo.td
+++ lib/Target/AMDGPU/SIInstrInfo.td
@@ -996,6 +996,12 @@
   let ParserMatchClass = MatchClass;
 }
 
+class NamedOperandBit_0<string Name, AsmOperandClass MatchClass> :
+  OperandWithDefaultOps<i1, (ops (i1 0))> {
+  let PrintMethod = "print"#Name;
+  let ParserMatchClass = MatchClass;
+}
+
 class NamedOperandU8<string Name, AsmOperandClass MatchClass> : Operand<i8> {
   let PrintMethod = "print"#Name;
   let ParserMatchClass = MatchClass;
@@ -1011,6 +1017,12 @@
   let ParserMatchClass = MatchClass;
 }
 
+class NamedOperandU32_0<string Name, AsmOperandClass MatchClass> :
+  OperandWithDefaultOps<i32, (ops (i32 0))> {
+  let PrintMethod = "print"#Name;
+  let ParserMatchClass = MatchClass;
+}
+
 class NamedOperandU32Default0<string Name, AsmOperandClass MatchClass> :
   OperandWithDefaultOps<i32, (ops (i32 0))> {
   let PrintMethod = "print"#Name;
@@ -1031,7 +1043,13 @@
 def gds : NamedOperandBit<"GDS", NamedMatchClass<"GDS">>;
 
 def omod : NamedOperandU32<"OModSI", NamedMatchClass<"OModSI">>;
+def omod0 : NamedOperandU32_0<"OModSI", NamedMatchClass<"OModSI">>;
+
+// We need to make the cases with a default of 0 distinct from no
+// default to help deal with some cases where the operand appears
+// before a mandatory operand.
 def clampmod : NamedOperandBit<"ClampSI", NamedMatchClass<"ClampSI">>;
+def clampmod0 : NamedOperandBit_0<"ClampSI", NamedMatchClass<"ClampSI">>;
 def highmod : NamedOperandBit<"High", NamedMatchClass<"High">>;
 
 def DLC : NamedOperandBit<"DLC", NamedMatchClass<"DLC">>;
@@ -1587,11 +1605,11 @@
       !if (!eq(HasModifiers, 1),
         // VOP1 with modifiers
         (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
-             clampmod:$clamp, omod:$omod)
+             clampmod0:$clamp, omod0:$omod)
       /* else */,
         // VOP1 without modifiers
         !if (!eq(HasIntClamp, 1),
-          (ins Src0RC:$src0, clampmod:$clamp),
+          (ins Src0RC:$src0, clampmod0:$clamp),
           (ins Src0RC:$src0))
       /* endif */ ),
     !if (!eq(NumSrcArgs, 2),
@@ -1600,14 +1618,14 @@
         !if( !eq(HasOMod, 1),
           (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
                Src1Mod:$src1_modifiers, Src1RC:$src1,
-               clampmod:$clamp, omod:$omod),
+               clampmod0:$clamp, omod0:$omod),
            (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
                Src1Mod:$src1_modifiers, Src1RC:$src1,
-               clampmod:$clamp))
+               clampmod0:$clamp))
       /* else */,
         // VOP2 without modifiers
         !if (!eq(HasIntClamp, 1),
-          (ins Src0RC:$src0, Src1RC:$src1, clampmod:$clamp),
+          (ins Src0RC:$src0, Src1RC:$src1, clampmod0:$clamp),
           (ins Src0RC:$src0, Src1RC:$src1))
 
       /* endif */ )
@@ -1619,12 +1637,12 @@
             (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
                  Src1Mod:$src1_modifiers, Src1RC:$src1,
                  Src2Mod:$src2_modifiers, Src2RC:$src2,
-                 clampmod:$clamp, omod:$omod),
+                 clampmod0:$clamp, omod0:$omod),
             !if (!eq(HasIntClamp, 1),
               (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
                    Src1Mod:$src1_modifiers, Src1RC:$src1,
                    Src2Mod:$src2_modifiers, Src2RC:$src2,
-                   clampmod:$clamp),
+                   clampmod0:$clamp),
               (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
                    Src1Mod:$src1_modifiers, Src1RC:$src1,
                    Src2Mod:$src2_modifiers, Src2RC:$src2))),
@@ -1632,18 +1650,18 @@
           !if (!eq(HasOMod, 1),
             (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
                  Src1Mod:$src1_modifiers, Src1RC:$src1,
-                 Src2RC:$src2, clampmod:$clamp, omod:$omod),
+                 Src2RC:$src2, clampmod0:$clamp, omod0:$omod),
             !if (!eq(HasIntClamp, 1),
               (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
                    Src1Mod:$src1_modifiers, Src1RC:$src1,
-                   Src2RC:$src2, clampmod:$clamp),
+                   Src2RC:$src2, clampmod0:$clamp),
               (ins Src0Mod:$src0_modifiers, Src0RC:$src0,
                    Src1Mod:$src1_modifiers, Src1RC:$src1,
                    Src2RC:$src2))))
       /* else */,
         // VOP3 without modifiers
         !if (!eq(HasIntClamp, 1),
-          (ins Src0RC:$src0, Src1RC:$src1, Src2RC:$src2, clampmod:$clamp),
+          (ins Src0RC:$src0, Src1RC:$src1, Src2RC:$src2, clampmod0:$clamp),
           (ins Src0RC:$src0, Src1RC:$src1, Src2RC:$src2))
       /* endif */ ))));
 }