Index: lib/Target/AMDGPU/SIInstrInfo.cpp
===================================================================
--- lib/Target/AMDGPU/SIInstrInfo.cpp
+++ lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -2066,12 +2066,40 @@
     if (Src2->isReg() && Src2->getReg() == Reg) {
       // Not allowed to use constant bus for another operand.
       // We can however allow an inline immediate as src0.
-      if (!Src0->isImm() &&
-          (Src0->isReg() && RI.isSGPRClass(MRI->getRegClass(Src0->getReg()))))
-        return false;
+      bool Src0Inlined = false;
+      if (Src0->isReg()) {
+        // Try to inline constant if possible.
+        // If the Def moves immediate and the use is single
+        // We are saving VGPR here.
+        MachineInstr *Def = MRI->getUniqueVRegDef(Src0->getReg());
+        if (Def && Def->isMoveImmediate() &&
+          isInlineConstant(Def->getOperand(1)) &&
+          MRI->hasOneUse(Src0->getReg())) {
+          Src0->ChangeToImmediate(Def->getOperand(1).getImm());
+          Src0Inlined = true;
+        } else if ((RI.isPhysicalRegister(Src0->getReg()) &&
+            RI.isSGPRClass(RI.getPhysRegClass(Src0->getReg()))) ||
+            (RI.isVirtualRegister(Src0->getReg()) &&
+            RI.isSGPRClass(MRI->getRegClass(Src0->getReg()))))
+          return false;
+          // VGPR is okay as Src0 - fallthrough
+      }
 
-      if (!Src1->isReg() || RI.isSGPRClass(MRI->getRegClass(Src1->getReg())))
-        return false;
+      if (Src1->isReg() && !Src0Inlined ) {
+        // We have one slot for inlinable constant so far - try to fill it
+        MachineInstr *Def = MRI->getUniqueVRegDef(Src1->getReg());
+        if (Def && Def->isMoveImmediate() &&
+            isInlineConstant(Def->getOperand(1)) &&
+            MRI->hasOneUse(Src1->getReg()) &&
+            commuteInstruction(UseMI)) {
+            Src0->ChangeToImmediate(Def->getOperand(1).getImm());
+        } else if ((RI.isPhysicalRegister(Src1->getReg()) &&
+            RI.isSGPRClass(RI.getPhysRegClass(Src1->getReg()))) ||
+            (RI.isVirtualRegister(Src1->getReg()) &&
+            RI.isSGPRClass(MRI->getRegClass(Src1->getReg()))))
+          return false;
+          // VGPR is okay as Src1 - fallthrough
+      }
 
       const int64_t Imm = ImmOp->getImm();
 
Index: test/CodeGen/AMDGPU/madak-inline-constant.mir
===================================================================
--- /dev/null
+++ test/CodeGen/AMDGPU/madak-inline-constant.mir
@@ -0,0 +1,185 @@
+# RUN: llc -march=amdgcn -run-pass peephole-opt -verify-machineinstrs -o - %s | FileCheck -check-prefix=GCN %s
+
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192
+# GCN:  S_MOV_B32 1082130432
+# GCN:  %3:vgpr_32 = V_MADAK_F32 1082130432, killed %0, 1092616192, implicit $exec
+
+---
+name:            test src1-inlined
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %18:sreg_32 = S_MOV_B32 1082130432
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed %0, 0, killed %18, 0, %17, 0, 0, implicit $exec
+
+...
+
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192
+# GCN:  S_MOV_B32 1082130432
+# GCN:  %3:vgpr_32 = V_MADAK_F32 1082130432, killed %0, 1092616192, implicit $exec
+
+---
+name:            test src0-inlined
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %18:sreg_32 = S_MOV_B32 1082130432
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed %18, 0, killed %0, 0, %17, 0, 0, implicit $exec
+
+...
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192
+# GCN:  S_MOV_B32 1082130432
+# GCN:  %3:vgpr_32 = V_MADAK_F32 killed %0, killed %0, 1092616192, implicit $exec
+
+---
+name:            test none-inlined
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %18:sreg_32 = S_MOV_B32 1082130432
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed %0, 0, killed %0, 0, %17, 0, 0, implicit $exec
+
+...
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192
+# GCN:  V_MOV_B32_e32 1082130432
+# GCN:  %3:vgpr_32 = V_MADAK_F32 1082130432, killed %0, 1092616192, implicit $exec
+
+---
+name:            test src1-2vgprs-inlined
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %18:vgpr_32 = V_MOV_B32_e32 1082130432, implicit $exec
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed %0, 0, killed %18, 0, %17, 0, 0, implicit $exec
+
+...
+
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192
+# GCN:  V_MOV_B32_e32 1082130432
+# GCN:  %3:vgpr_32 = V_MADAK_F32 1082130432, killed %0, 1092616192, implicit $exec
+
+---
+name:            test src0-2vgprs-inlined
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %18:vgpr_32 = V_MOV_B32_e32 1082130432, implicit $exec
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed %18, 0, killed %0, 0, %17, 0, 0, implicit $exec
+
+...
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192, implicit $exec
+# GCN:  S_MOV_B32 1082130432
+# GCN:  V_MADAK_F32 1082130432, killed $vgpr1, 1092616192, implicit $exec
+
+---
+name:            test src0-phys-vgpr
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1
+  
+
+    $vgpr1 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %18:sgpr_32 = S_MOV_B32 1082130432
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed $vgpr1, 0, killed %18, 0, %17, 0, 0, implicit $exec
+
+...
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192, implicit $exec
+# GCN:  S_MOV_B32 1082130432
+# GCN:  V_MADAK_F32 1082130432, killed $vgpr0, 1092616192, implicit $exec
+
+---
+name:            test src1-phys-vgpr
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1
+  
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %18:sgpr_32 = S_MOV_B32 1082130432
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed %18, 0, killed $vgpr0, 0, %17, 0, 0, implicit $exec
+
+...
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192, implicit $exec
+# GCN:  V_MAC_F32_e64 0, killed $sgpr2, 0, killed %0, 0, %1, 0, 0, implicit $exec
+
+---
+name:            test src0-phys-sgpr
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1, $sgpr2
+  
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed $sgpr2, 0, killed %0, 0, %17, 0, 0, implicit $exec
+
+...
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192, implicit $exec
+# GCN:  V_MAC_F32_e64 0, killed %0, 0, killed $sgpr2, 0, %1, 0, 0, implicit $exec
+
+---
+name:            test src1-phys-sgpr
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1, $sgpr2
+  
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed %0, 0, killed $sgpr2, 0, %17, 0, 0, implicit $exec
+
+...
+
+# GCN-LABEL: bb.0:
+# GCN:  V_MOV_B32_e32 1092616192, implicit $exec
+# GCN:  $sgpr2 = S_MOV_B32 1082130432
+# GCN:  V_MADAK_F32 1082130432, killed %0, 1092616192, implicit $exec
+
+---
+name:            test src1-phys-sgpr-move
+body:             |
+  bb.0:
+    liveins: $vgpr0, $sgpr0_sgpr1
+  
+
+    %0:vgpr_32 = COPY $vgpr0
+    %17:vgpr_32 = V_MOV_B32_e32 1092616192, implicit $exec
+    $sgpr2 = S_MOV_B32 1082130432
+    %19:vgpr_32 = V_MAC_F32_e64 0, killed %0, 0, killed $sgpr2, 0, %17, 0, 0, implicit $exec
+
+...