diff --git a/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def b/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def
index 3a58c6c6a29f..eed0bff7c399 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def
+++ b/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def
@@ -16,34 +16,36 @@ namespace AMDGPU {
 
 enum PartialMappingIdx {
   None = - 1,
-  PM_SGPR1  = 0,
-  PM_SGPR16 = 4,
-  PM_SGPR32 = 5,
-  PM_SGPR64 = 6,
-  PM_SGPR128 = 7,
-  PM_SGPR256 = 8,
-  PM_SGPR512 = 9,
-  PM_VGPR1  = 10,
-  PM_VGPR16 = 14,
-  PM_VGPR32 = 15,
-  PM_VGPR64 = 16,
-  PM_VGPR128 = 17,
-  PM_VGPR256 = 18,
-  PM_VGPR512 = 19,
-  PM_SGPR96 = 20,
-  PM_VGPR96 = 21
+  PM_SGPR1  = 1,
+  PM_SGPR16 = 5,
+  PM_SGPR32 = 6,
+  PM_SGPR64 = 7,
+  PM_SGPR128 = 8,
+  PM_SGPR256 = 9,
+  PM_SGPR512 = 10,
+  PM_VGPR1  = 11,
+  PM_VGPR16 = 15,
+  PM_VGPR32 = 16,
+  PM_VGPR64 = 17,
+  PM_VGPR128 = 18,
+  PM_VGPR256 = 19,
+  PM_VGPR512 = 20,
+  PM_SGPR96 = 21,
+  PM_VGPR96 = 22
 };
 
 const RegisterBankInfo::PartialMapping PartMappings[] {
   // StartIdx, Length, RegBank
   {0, 1,  SCCRegBank},
+  {0, 1,  SGPRRegBank}, // SGPR begin
   {0, 16, SGPRRegBank},
   {0, 32, SGPRRegBank},
   {0, 64, SGPRRegBank},
   {0, 128, SGPRRegBank},
   {0, 256, SGPRRegBank},
   {0, 512, SGPRRegBank},
-  {0, 1,  SGPRRegBank},
+
+  {0, 1,  VGPRRegBank}, // VGPR begin
   {0, 16, VGPRRegBank},
   {0, 32, VGPRRegBank},
   {0, 64, VGPRRegBank},
@@ -55,33 +57,40 @@ const RegisterBankInfo::PartialMapping PartMappings[] {
 };
 
 const RegisterBankInfo::ValueMapping ValMappings[] {
+  // SCC
   {&PartMappings[0], 1},
-  {nullptr, 0},
-  {nullptr, 0},
-  {nullptr, 0},
+
+  // SGPRs
   {&PartMappings[1], 1},
+  {nullptr, 0}, // Illegal power of 2 sizes
+  {nullptr, 0},
+  {nullptr, 0},
   {&PartMappings[2], 1},
   {&PartMappings[3], 1},
   {&PartMappings[4], 1},
   {&PartMappings[5], 1},
   {&PartMappings[6], 1},
   {&PartMappings[7], 1},
-  {nullptr, 0},
-  {nullptr, 0},
-  {nullptr, 0},
+
+    // VGPRs
   {&PartMappings[8], 1},
+  {nullptr, 0},
+  {nullptr, 0},
+  {nullptr, 0},
   {&PartMappings[9], 1},
   {&PartMappings[10], 1},
   {&PartMappings[11], 1},
   {&PartMappings[12], 1},
   {&PartMappings[13], 1},
   {&PartMappings[14], 1},
-  {&PartMappings[15], 1}
+  {&PartMappings[15], 1},
+  {&PartMappings[16], 1}
 };
 
 enum ValueMappingIdx {
-  SGPRStartIdx = 0,
-  VGPRStartIdx = 10
+  SCCStartIdx = 0,
+  SGPRStartIdx = 1,
+  VGPRStartIdx = 11
 };
 
 const RegisterBankInfo::ValueMapping *getValueMapping(unsigned BankID,
@@ -89,7 +98,9 @@ const RegisterBankInfo::ValueMapping *getValueMapping(unsigned BankID,
   unsigned Idx;
   switch (Size) {
   case 1:
-    Idx = BankID == AMDGPU::SCCRegBankID ? PM_SGPR1 : PM_VGPR1;
+    if (BankID == AMDGPU::SCCRegBankID)
+      return &ValMappings[0];
+    Idx = BankID == AMDGPU::SGPRRegBankID ? PM_SGPR1 : PM_VGPR1;
     break;
   case 96:
     Idx = BankID == AMDGPU::SGPRRegBankID ? PM_SGPR96 : PM_VGPR96;
@@ -99,6 +110,10 @@ const RegisterBankInfo::ValueMapping *getValueMapping(unsigned BankID,
     Idx += Log2_32_Ceil(Size);
     break;
   }
+
+  assert(Log2_32_Ceil(Size) == Log2_32_Ceil(ValMappings[Idx].BreakDown->Length));
+  assert(BankID == ValMappings[Idx].BreakDown->RegBank->getID());
+
   return &ValMappings[Idx];
 }
 
diff --git a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
index bf218f7c4b90..bf43fb5ad038 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
@@ -475,7 +475,7 @@ AMDGPURegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
   case AMDGPU::G_FCMP: {
     unsigned Size = MRI.getType(MI.getOperand(2).getReg()).getSizeInBits();
     unsigned Op2Bank = getRegBankID(MI.getOperand(2).getReg(), MRI, *TRI);
-    OpdsMapping[0] = AMDGPU::getValueMapping(AMDGPU::VGPRRegBankID, 1);
+    OpdsMapping[0] = AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, 1);
     OpdsMapping[1] = nullptr; // Predicate Operand.
     OpdsMapping[2] = AMDGPU::getValueMapping(Op2Bank, Size);
     OpdsMapping[3] = AMDGPU::getValueMapping(AMDGPU::VGPRRegBankID, Size);
@@ -515,7 +515,7 @@ AMDGPURegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
     unsigned Op3Bank = getRegBankID(MI.getOperand(3).getReg(), MRI, *TRI);
     unsigned Op0Bank = Op2Bank == AMDGPU::SGPRRegBankID &&
                        Op3Bank == AMDGPU::SGPRRegBankID ?
-                       AMDGPU::SCCRegBankID : AMDGPU::VGPRRegBankID;
+                       AMDGPU::SCCRegBankID : AMDGPU::SGPRRegBankID;
     OpdsMapping[0] = AMDGPU::getValueMapping(Op0Bank, 1);
     OpdsMapping[1] = nullptr; // Predicate Operand.
     OpdsMapping[2] = AMDGPU::getValueMapping(Op2Bank, Size);
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-trunc.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-trunc.mir
index 14de218554f4..d171d9f9f9bf 100644
--- a/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-trunc.mir
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-trunc.mir
@@ -10,7 +10,7 @@ body: |
   bb.0:
     liveins: $sgpr0_sgpr1
     ; CHECK-LABEL: name: trunc_i64_to_i32_s
-    ; CHECK: [[COPY:%[0-9]+]]:sgpr(s64) = COPY $sgpr0
+    ; CHECK: [[COPY:%[0-9]+]]:sgpr(s64) = COPY $sgpr0_sgpr1
     ; CHECK: [[TRUNC:%[0-9]+]]:sgpr(s32) = G_TRUNC [[COPY]](s64)
     %0:_(s64) = COPY $sgpr0_sgpr1
     %1:_(s32) = G_TRUNC %0
@@ -24,8 +24,63 @@ body: |
   bb.0:
     liveins: $vgpr0_vgpr1
     ; CHECK-LABEL: name: trunc_i64_to_i32_v
-    ; CHECK: [[COPY:%[0-9]+]]:vgpr(s64) = COPY $vgpr0
+    ; CHECK: [[COPY:%[0-9]+]]:vgpr(s64) = COPY $vgpr0_vgpr1
     ; CHECK: [[TRUNC:%[0-9]+]]:vgpr(s32) = G_TRUNC [[COPY]](s64)
     %0:_(s64) = COPY $vgpr0_vgpr1
     %1:_(s32) = G_TRUNC %0
 ...
+---
+name: trunc_i64_to_i1_s
+legalized: true
+
+body: |
+  bb.0:
+    liveins: $sgpr0_sgpr1
+    ; CHECK-LABEL: name: trunc_i64_to_i1_s
+    ; CHECK: [[COPY:%[0-9]+]]:sgpr(s64) = COPY $sgpr0_sgpr1
+    ; CHECK: [[TRUNC:%[0-9]+]]:sgpr(s1) = G_TRUNC [[COPY]](s64)
+    %0:_(s64) = COPY $sgpr0_sgpr1
+    %1:_(s1) = G_TRUNC %0
+...
+
+---
+name: trunc_i64_to_i1_v
+legalized: true
+
+body: |
+  bb.0:
+    liveins: $vgpr0_vgpr1
+    ; CHECK-LABEL: name: trunc_i64_to_i1_v
+    ; CHECK: [[COPY:%[0-9]+]]:vgpr(s64) = COPY $vgpr0_vgpr1
+    ; CHECK: [[TRUNC:%[0-9]+]]:vgpr(s1) = G_TRUNC [[COPY]](s64)
+    %0:_(s64) = COPY $vgpr0_vgpr1
+    %1:_(s1) = G_TRUNC %0
+...
+
+---
+name: trunc_i32_to_i1_s
+legalized: true
+
+body: |
+  bb.0:
+    liveins: $sgpr0
+    ; CHECK-LABEL: name: trunc_i32_to_i1_s
+    ; CHECK: [[COPY:%[0-9]+]]:sgpr(s32) = COPY $sgpr0
+    ; CHECK: [[TRUNC:%[0-9]+]]:sgpr(s1) = G_TRUNC [[COPY]](s32)
+    %0:_(s32) = COPY $sgpr0
+    %1:_(s1) = G_TRUNC %0
+...
+
+---
+name: trunc_i32_to_i1_v
+legalized: true
+
+body: |
+  bb.0:
+    liveins: $vgpr0
+    ; CHECK-LABEL: name: trunc_i32_to_i1_v
+    ; CHECK: [[COPY:%[0-9]+]]:vgpr(s32) = COPY $vgpr0
+    ; CHECK: [[TRUNC:%[0-9]+]]:vgpr(s1) = G_TRUNC [[COPY]](s32)
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s1) = G_TRUNC %0
+...