Index: lib/Target/AMDGPU/SIInstrInfo.cpp
===================================================================
--- lib/Target/AMDGPU/SIInstrInfo.cpp
+++ lib/Target/AMDGPU/SIInstrInfo.cpp
@@ -1555,8 +1555,9 @@
   //   buzz;
 
   RS->enterBasicBlockEnd(MBB);
-  unsigned Scav = RS->scavengeRegister(&AMDGPU::SReg_64RegClass,
-                                       MachineBasicBlock::iterator(GetPC), 0);
+  unsigned Scav = RS->scavengeRegisterBackwards(
+    AMDGPU::SReg_64RegClass,
+    MachineBasicBlock::iterator(GetPC), false, 0);
   MRI.replaceRegWith(PCReg, Scav);
   MRI.clearVirtRegs();
   RS->setRegUsed(Scav);
Index: test/CodeGen/AMDGPU/branch-relaxation.ll
===================================================================
--- test/CodeGen/AMDGPU/branch-relaxation.ll
+++ test/CodeGen/AMDGPU/branch-relaxation.ll
@@ -1,4 +1,4 @@
-; RUN: llc -march=amdgcn -mcpu=tahiti -verify-machineinstrs -amdgpu-s-branch-bits=4 < %s | FileCheck -check-prefix=GCN %s
+; RUN: llc -march=amdgcn -mcpu=tahiti -verify-machineinstrs -amdgpu-s-branch-bits=4 < %s | FileCheck -enable-var-scope -check-prefix=GCN %s
 
 
 ; FIXME: We should use llvm-mc for this, but we can't even parse our own output.
@@ -61,10 +61,10 @@
 ; GCN-NEXT: s_cbranch_scc0 [[LONGBB:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: [[LONG_JUMP:BB[0-9]+_[0-9]+]]: ; %bb0
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[ENDBB:BB[0-9]+_[0-9]+]]-([[LONG_JUMP]]+4)
-; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0
-; GCN-NEXT: s_setpc_b64 vcc
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC_LO:[0-9]+]]:[[PC_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_add_u32 s[[PC_LO]], s[[PC_LO]], [[ENDBB:BB[0-9]+_[0-9]+]]-([[LONG_JUMP]]+4)
+; GCN-NEXT: s_addc_u32 s[[PC_HI]], s[[PC_HI]], 0
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC_LO]]:[[PC_HI]]{{\]}}
 
 ; GCN-NEXT: [[LONGBB]]:
 ; GCN-NEXT: ;;#ASMSTART
@@ -105,10 +105,10 @@
 ; GCN: s_cbranch_vccz [[LONGBB:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: [[LONG_JUMP:BB[0-9]+_[0-9]+]]: ; %bb0
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[ENDBB:BB[0-9]+_[0-9]+]]-([[LONG_JUMP]]+4)
-; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0
-; GCN-NEXT: s_setpc_b64 vcc
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC_LO:[0-9]+]]:[[PC_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_add_u32 s[[PC_LO]], s[[PC_LO]], [[ENDBB:BB[0-9]+_[0-9]+]]-([[LONG_JUMP]]+4)
+; GCN-NEXT: s_addc_u32 s[[PC_HI]], s[[PC_HI]], 0
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC_LO]]:[[PC_HI]]{{\]}}
 
 ; GCN-NEXT: [[LONGBB]]:
 ; GCN: v_nop_e64
@@ -191,10 +191,11 @@
 
 ; GCN-NEXT: [[LONG_JUMP:BB[0-9]+_[0-9]+]]: ; %bb2
 ; GCN-NEXT: ; in Loop: Header=[[LOOPBB]] Depth=1
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_sub_u32 vcc_lo, vcc_lo, ([[LONG_JUMP]]+4)-[[LOOPBB]]
-; GCN-NEXT: s_subb_u32 vcc_hi, vcc_hi, 0
-; GCN-NEXT: s_setpc_b64 vcc
+
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC_LO:[0-9]+]]:[[PC_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_sub_u32 s[[PC_LO]], s[[PC_LO]], ([[LONG_JUMP]]+4)-[[LOOPBB]]
+; GCN-NEXT: s_subb_u32 s[[PC_HI]], s[[PC_HI]], 0
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC_LO]]:[[PC_HI]]{{\]}}
 
 ; GCN-NEXT: [[ENDBB]]:
 ; GCN-NEXT: s_endpgm
@@ -225,20 +226,20 @@
 ; GCN-NEXT: s_cbranch_scc0 [[BB2:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: [[LONG_JUMP0:BB[0-9]+_[0-9]+]]: ; %bb0
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[BB3:BB[0-9]_[0-9]+]]-([[LONG_JUMP0]]+4)
-; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0{{$}}
-; GCN-NEXT: s_setpc_b64 vcc
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC0_LO:[0-9]+]]:[[PC0_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_add_u32 s[[PC0_LO]], s[[PC0_LO]], [[BB3:BB[0-9]_[0-9]+]]-([[LONG_JUMP0]]+4)
+; GCN-NEXT: s_addc_u32 s[[PC0_HI]], s[[PC0_HI]], 0{{$}}
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC0_LO]]:[[PC0_HI]]{{\]}}
 
 ; GCN-NEXT: [[BB2]]: ; %bb2
 ; GCN: v_mov_b32_e32 [[BB2_K:v[0-9]+]], 17
 ; GCN: buffer_store_dword [[BB2_K]]
 
 ; GCN-NEXT: [[LONG_JUMP1:BB[0-9]+_[0-9]+]]: ; %bb2
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[BB4:BB[0-9]_[0-9]+]]-([[LONG_JUMP1]]+4)
-; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0{{$}}
-; GCN-NEXT: s_setpc_b64 vcc
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC1_LO:[0-9]+]]:[[PC1_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_add_u32 s[[PC1_LO]], s[[PC1_LO]], [[BB4:BB[0-9]_[0-9]+]]-([[LONG_JUMP1]]+4)
+; GCN-NEXT: s_addc_u32 s[[PC1_HI]], s[[PC1_HI]], 0{{$}}
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC1_LO]]:[[PC1_HI]]{{\]}}
 
 ; GCN: [[BB3]]: ; %bb3
 ; GCN: v_nop_e64
@@ -289,10 +290,11 @@
 
 ; GCN-NEXT: [[LONGBB:BB[0-9]+_[0-9]+]]: ; %loop
 ; GCN-NEXT: ; in Loop: Header=[[LOOP]] Depth=1
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_sub_u32 vcc_lo, vcc_lo, ([[LONGBB]]+4)-[[LOOP]]
-; GCN-NEXT: s_subb_u32 vcc_hi, vcc_hi, 0{{$}}
-; GCN-NEXT: s_setpc_b64 vcc
+
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC_LO:[0-9]+]]:[[PC_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_sub_u32 s[[PC_LO]], s[[PC_LO]], ([[LONGBB]]+4)-[[LOOP]]
+; GCN-NEXT: s_subb_u32 s[[PC_HI]], s[[PC_HI]], 0{{$}}
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC_LO]]:[[PC_HI]]{{\]}}
 ; GCN-NEXT .Lfunc_end{{[0-9]+}}:
 define amdgpu_kernel void @uniform_unconditional_min_long_backward_branch(i32 addrspace(1)* %arg, i32 %arg1) {
 entry:
@@ -318,10 +320,11 @@
 ; GCN-NEXT: s_cbranch_scc0 [[BB1:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: [[LONGBB0:BB[0-9]+_[0-9]+]]: ; %bb0
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[BB2:BB[0-9]_[0-9]+]]-([[LONGBB0]]+4)
-; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0{{$}}
-; GCN-NEXT: s_setpc_b64 vcc
+
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC0_LO:[0-9]+]]:[[PC0_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_add_u32 s[[PC0_LO]], s[[PC0_LO]], [[BB2:BB[0-9]_[0-9]+]]-([[LONGBB0]]+4)
+; GCN-NEXT: s_addc_u32 s[[PC0_HI]], s[[PC0_HI]], 0{{$}}
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC0_LO]]:[[PC0_HI]]{{\]}}
 
 ; GCN-NEXT: [[BB1]]: ; %bb1
 ; GCN-NEXT: s_load_dword
@@ -330,10 +333,10 @@
 ; GCN-NEXT: s_cbranch_scc0 [[BB2:BB[0-9]_[0-9]+]]
 
 ; GCN-NEXT: [[LONGBB1:BB[0-9]+_[0-9]+]]: ; %bb1
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[BB3:BB[0-9]+_[0-9]+]]-([[LONGBB1]]+4)
-; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0{{$}}
-; GCN-NEXT: s_setpc_b64 vcc
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC1_LO:[0-9]+]]:[[PC1_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_add_u32 s[[PC1_LO]], s[[PC1_LO]], [[BB3:BB[0-9]+_[0-9]+]]-([[LONGBB1]]+4)
+; GCN-NEXT: s_addc_u32 s[[PC1_HI]], s[[PC1_HI]], 0{{$}}
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC1_LO]]:[[PC1_HI]]{{\]}}
 
 ; GCN-NEXT: [[BB2]]: ; %bb2
 ; GCN-NEXT: ;;#ASMSTART
@@ -389,10 +392,10 @@
 ; GCN-NEXT: s_cbranch_execnz [[IF:BB[0-9]+_[0-9]+]]
 
 ; GCN-NEXT: [[LONGBB:BB[0-9]+_[0-9]+]]: ; %entry
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_add_u32 vcc_lo, vcc_lo, [[BB2:BB[0-9]_[0-9]+]]-([[LONGBB]]+4)
-; GCN-NEXT: s_addc_u32 vcc_hi, vcc_hi, 0{{$}}
-; GCN-NEXT: s_setpc_b64 vcc
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC_LO:[0-9]+]]:[[PC_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_add_u32 s[[PC_LO]], s[[PC_LO]], [[BB2:BB[0-9]_[0-9]+]]-([[LONGBB]]+4)
+; GCN-NEXT: s_addc_u32 s[[PC_HI]], s[[PC_HI]], 0{{$}}
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC_LO]]:[[PC_HI]]{{\]}}
 
 ; GCN-NEXT: [[IF]]: ; %if
 ; GCN: buffer_store_dword
@@ -454,10 +457,10 @@
 
 ; GCN-NEXT: [[LONGBB:BB[0-9]+_[0-9]+]]: ; %loop
 ; GCN-NEXT: ; in Loop: Header=[[LOOP_BODY]] Depth=1
-; GCN-NEXT: s_getpc_b64 vcc
-; GCN-NEXT: s_sub_u32 vcc_lo, vcc_lo, ([[LONGBB]]+4)-[[LOOP_BODY]]
-; GCN-NEXT: s_subb_u32 vcc_hi, vcc_hi, 0
-; GCN-NEXT: s_setpc_b64 vcc
+; GCN-NEXT: s_getpc_b64 s{{\[}}[[PC_LO:[0-9]+]]:[[PC_HI:[0-9]+]]{{\]}}
+; GCN-NEXT: s_sub_u32 s[[PC_LO]], s[[PC_LO]], ([[LONGBB]]+4)-[[LOOP_BODY]]
+; GCN-NEXT: s_subb_u32 s[[PC_HI]], s[[PC_HI]], 0
+; GCN-NEXT: s_setpc_b64 s{{\[}}[[PC_LO]]:[[PC_HI]]{{\]}}
 
 ; GCN-NEXT: [[RET]]: ; %UnifiedReturnBlock
 ; GCN-NEXT: s_endpgm
@@ -494,8 +497,9 @@
 ; GCN-NEXT: s_branch [[LONG_BR_0:BB[0-9]+_[0-9]+]]
 ; GCN-NEXT: BB{{[0-9]+_[0-9]+}}:
 
-; GCN: s_add_u32 vcc_lo, vcc_lo, [[LONG_BR_DEST0:BB[0-9]+_[0-9]+]]-(
-; GCN: s_setpc_b64
+; GCN: s_add_u32 s{{[0-9]+}}, s{{[0-9]+}}, [[LONG_BR_DEST0:BB[0-9]+_[0-9]+]]-(
+; GCN-NEXT: s_addc_u32
+; GCN-NEXT: s_setpc_b64
 
 ; GCN-NEXT: [[LONG_BR_0]]:
 ; GCN-DAG: v_cmp_lt_i32