Index: llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -2003,6 +2003,13 @@
     Observer.changedInstr(MI);
     return Legalized;
 
+  case TargetOpcode::G_ABS:
+    Observer.changingInstr(MI);
+    widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
+    widenScalarDst(MI, WideTy);
+    Observer.changedInstr(MI);
+    return Legalized;
+
   case TargetOpcode::G_ADD:
   case TargetOpcode::G_AND:
   case TargetOpcode::G_MUL:
@@ -4093,6 +4100,7 @@
   case G_PTR_ADD:
   case G_SMULH:
   case G_UMULH:
+  case G_ABS:
   case G_FADD:
   case G_FMUL:
   case G_FSUB:
Index: llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
+++ llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
@@ -993,6 +993,11 @@
       .lower();
   }
 
+  getActionDefinitionsBuilder(G_ABS)
+    .legalFor({S32, S16})
+    .scalarize(0)
+    .lower();
+
   getActionDefinitionsBuilder(G_INTTOPTR)
     // List the common cases
     .legalForCartesianProduct(AddrSpaces64, {S64})
Index: llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
===================================================================
--- llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
+++ llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
@@ -2307,6 +2307,7 @@
     MI.eraseFromParent();
     return;
   }
+  case AMDGPU::G_ABS:
   case AMDGPU::G_ADD:
   case AMDGPU::G_SUB:
   case AMDGPU::G_MUL:
@@ -3475,6 +3476,7 @@
   }
   case AMDGPU::G_PTR_ADD:
   case AMDGPU::G_PTRMASK:
+  case AMDGPU::G_ABS:
   case AMDGPU::G_ADD:
   case AMDGPU::G_SUB:
   case AMDGPU::G_MUL:
Index: llvm/lib/Target/AMDGPU/SOPInstructions.td
===================================================================
--- llvm/lib/Target/AMDGPU/SOPInstructions.td
+++ llvm/lib/Target/AMDGPU/SOPInstructions.td
@@ -1365,6 +1365,10 @@
   (S_SEXT_I32_I16 $src)
 >;
 
+def : GCNPat <
+  (i32 (abs SReg_32:$src)),
+  (S_ABS_I32 SReg_32:$src)
+>;
 
 //===----------------------------------------------------------------------===//
 // SOP2 Patterns
Index: llvm/lib/Target/AMDGPU/VOP3Instructions.td
===================================================================
--- llvm/lib/Target/AMDGPU/VOP3Instructions.td
+++ llvm/lib/Target/AMDGPU/VOP3Instructions.td
@@ -754,6 +754,31 @@
 def : DivFmasPat<f64, V_DIV_FMAS_F64_e64, VCC_LO>;
 }
 
+let SubtargetPredicate = isGFX8Plus in {
+def : GCNPat <
+  (i32 (abs i32:$src)),
+  (V_MAX_I32_e32 (V_SUB_I32_e64 (i32 0), VGPR_32:$src), VGPR_32:$src)
+>;
+def : GCNPat <
+  (i16 (abs i16:$src)),
+  (V_MAX_I16_e64 (V_SUB_U16_e64 (i16 0), i16:$src), i16:$src)
+>;
+}
+
+let SubtargetPredicate = isGFX6GFX7 in {
+def : GCNPat <
+  (i32 (abs i32:$src)),
+  (V_MAX_I32_e32 (V_SUB_CO_U32_e32 (i32 0), VGPR_32:$src), VGPR_32:$src)
+>;
+def : GCNPat <
+  (i16 (abs i16:$src)),
+  (V_MAX_I32_e32
+    (V_SUB_CO_U32_e32 (i16 0),
+                      (V_BFE_I32_e64 i16:$src, (i16 0), (i16 16))),
+    (V_BFE_I32_e64 i16:$src, (i16 0), (i16 16)))
+>;
+}
+
 //===----------------------------------------------------------------------===//
 // Integer Clamp Patterns
 //===----------------------------------------------------------------------===//
Index: llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.abs.ll
===================================================================
--- /dev/null
+++ llvm/test/CodeGen/AMDGPU/GlobalISel/llvm.abs.ll
@@ -0,0 +1,153 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -global-isel -march=amdgcn -mcpu=tahiti -verify-machineinstrs -o - < %s | FileCheck %s --check-prefixes=GFX,GFX6
+; RUN: llc -global-isel -march=amdgcn -mcpu=fiji -verify-machineinstrs -o - < %s | FileCheck %s --check-prefixes=GFX,GFX8
+
+declare i16 @llvm.abs.i16(i16, i1)
+declare i32 @llvm.abs.i32(i32, i1)
+declare i64 @llvm.abs.i64(i64, i1)
+declare <4 x i32> @llvm.abs.v4i32(<4 x i32>, i1)
+
+define amdgpu_cs i16 @abs_sgrp_i16(i16 inreg %arg) {
+; GFX-LABEL: abs_sgrp_i16:
+; GFX:       ; %bb.0:
+; GFX-NEXT:    s_abs_i32 s0, s0
+; GFX-NEXT:    ; return to shader part epilog
+  %res = call i16 @llvm.abs.i16(i16 %arg, i1 false)
+  ret i16 %res
+}
+
+define amdgpu_cs i32 @abs_sgrp_i32(i32 inreg %arg) {
+; GFX-LABEL: abs_sgrp_i32:
+; GFX:       ; %bb.0:
+; GFX-NEXT:    s_abs_i32 s0, s0
+; GFX-NEXT:    ; return to shader part epilog
+  %res = call i32 @llvm.abs.i32(i32 %arg, i1 false)
+  ret i32 %res
+}
+
+define amdgpu_cs i64 @abs_sgrp_i64(i64 inreg %arg) {
+; GFX-LABEL: abs_sgrp_i64:
+; GFX:       ; %bb.0:
+; GFX-NEXT:    s_ashr_i32 s2, s1, 31
+; GFX-NEXT:    s_add_u32 s0, s0, s2
+; GFX-NEXT:    s_cselect_b32 s4, 1, 0
+; GFX-NEXT:    s_and_b32 s4, s4, 1
+; GFX-NEXT:    s_cmp_lg_u32 s4, 0
+; GFX-NEXT:    s_mov_b32 s3, s2
+; GFX-NEXT:    s_addc_u32 s1, s1, s2
+; GFX-NEXT:    s_xor_b64 s[0:1], s[0:1], s[2:3]
+; GFX-NEXT:    ; return to shader part epilog
+  %res = call i64 @llvm.abs.i64(i64 %arg, i1 false)
+  ret i64 %res
+}
+
+define amdgpu_cs <4 x i32> @abs_sgrp_v4i32(<4 x i32> inreg %arg) {
+; GFX-LABEL: abs_sgrp_v4i32:
+; GFX:       ; %bb.0:
+; GFX-NEXT:    s_abs_i32 s0, s0
+; GFX-NEXT:    s_abs_i32 s1, s1
+; GFX-NEXT:    s_abs_i32 s2, s2
+; GFX-NEXT:    s_abs_i32 s3, s3
+; GFX-NEXT:    ; return to shader part epilog
+  %res = call <4 x i32> @llvm.abs.v4i32(<4 x i32> %arg, i1 false)
+  ret <4 x i32> %res
+}
+
+define amdgpu_cs i16 @abs_vgpr_i16(i16 %arg) {
+; GFX6-LABEL: abs_vgpr_i16:
+; GFX6:       ; %bb.0:
+; GFX6-NEXT:    v_bfe_i32 v0, v0, 0, 16
+; GFX6-NEXT:    v_sub_i32_e32 v1, vcc, 0, v0
+; GFX6-NEXT:    v_max_i32_e32 v0, v1, v0
+; GFX6-NEXT:    v_readfirstlane_b32 s0, v0
+; GFX6-NEXT:    ; return to shader part epilog
+;
+; GFX8-LABEL: abs_vgpr_i16:
+; GFX8:       ; %bb.0:
+; GFX8-NEXT:    v_sub_u16_e32 v1, 0, v0
+; GFX8-NEXT:    v_max_i16_e32 v0, v1, v0
+; GFX8-NEXT:    v_readfirstlane_b32 s0, v0
+; GFX8-NEXT:    ; return to shader part epilog
+  %res = call i16 @llvm.abs.i16(i16 %arg, i1 false)
+  ret i16 %res
+}
+
+define amdgpu_cs i32 @abs_vgpr_i32(i32 %arg) {
+; GFX6-LABEL: abs_vgpr_i32:
+; GFX6:       ; %bb.0:
+; GFX6-NEXT:    v_sub_i32_e32 v1, vcc, 0, v0
+; GFX6-NEXT:    v_max_i32_e32 v0, v1, v0
+; GFX6-NEXT:    v_readfirstlane_b32 s0, v0
+; GFX6-NEXT:    ; return to shader part epilog
+;
+; GFX8-LABEL: abs_vgpr_i32:
+; GFX8:       ; %bb.0:
+; GFX8-NEXT:    v_sub_i32 v1, 0, v0
+; GFX8-NEXT:    v_max_i32_e32 v0, v1, v0
+; GFX8-NEXT:    v_readfirstlane_b32 s0, v0
+; GFX8-NEXT:    ; return to shader part epilog
+  %res = call i32 @llvm.abs.i32(i32 %arg, i1 false)
+  ret i32 %res
+}
+
+define amdgpu_cs i64 @abs_vgpr_i64(i64 %arg) {
+; GFX6-LABEL: abs_vgpr_i64:
+; GFX6:       ; %bb.0:
+; GFX6-NEXT:    v_ashrrev_i32_e32 v2, 31, v1
+; GFX6-NEXT:    v_add_i32_e32 v0, vcc, v0, v2
+; GFX6-NEXT:    v_addc_u32_e32 v1, vcc, v1, v2, vcc
+; GFX6-NEXT:    v_xor_b32_e32 v0, v0, v2
+; GFX6-NEXT:    v_xor_b32_e32 v1, v1, v2
+; GFX6-NEXT:    v_readfirstlane_b32 s0, v0
+; GFX6-NEXT:    v_readfirstlane_b32 s1, v1
+; GFX6-NEXT:    ; return to shader part epilog
+;
+; GFX8-LABEL: abs_vgpr_i64:
+; GFX8:       ; %bb.0:
+; GFX8-NEXT:    v_ashrrev_i32_e32 v2, 31, v1
+; GFX8-NEXT:    v_add_u32_e32 v0, vcc, v0, v2
+; GFX8-NEXT:    v_addc_u32_e32 v1, vcc, v1, v2, vcc
+; GFX8-NEXT:    v_xor_b32_e32 v0, v0, v2
+; GFX8-NEXT:    v_xor_b32_e32 v1, v1, v2
+; GFX8-NEXT:    v_readfirstlane_b32 s0, v0
+; GFX8-NEXT:    v_readfirstlane_b32 s1, v1
+; GFX8-NEXT:    ; return to shader part epilog
+  %res = call i64 @llvm.abs.i64(i64 %arg, i1 false)
+  ret i64 %res
+}
+
+define amdgpu_cs <4 x i32> @abs_vgpr_v4i32(<4 x i32> %arg) {
+; GFX6-LABEL: abs_vgpr_v4i32:
+; GFX6:       ; %bb.0:
+; GFX6-NEXT:    v_sub_i32_e32 v4, vcc, 0, v0
+; GFX6-NEXT:    v_max_i32_e32 v0, v4, v0
+; GFX6-NEXT:    v_sub_i32_e32 v4, vcc, 0, v1
+; GFX6-NEXT:    v_max_i32_e32 v1, v4, v1
+; GFX6-NEXT:    v_sub_i32_e32 v4, vcc, 0, v2
+; GFX6-NEXT:    v_max_i32_e32 v2, v4, v2
+; GFX6-NEXT:    v_sub_i32_e32 v4, vcc, 0, v3
+; GFX6-NEXT:    v_max_i32_e32 v3, v4, v3
+; GFX6-NEXT:    v_readfirstlane_b32 s0, v0
+; GFX6-NEXT:    v_readfirstlane_b32 s1, v1
+; GFX6-NEXT:    v_readfirstlane_b32 s2, v2
+; GFX6-NEXT:    v_readfirstlane_b32 s3, v3
+; GFX6-NEXT:    ; return to shader part epilog
+;
+; GFX8-LABEL: abs_vgpr_v4i32:
+; GFX8:       ; %bb.0:
+; GFX8-NEXT:    v_sub_i32 v4, 0, v0
+; GFX8-NEXT:    v_max_i32_e32 v0, v4, v0
+; GFX8-NEXT:    v_sub_i32 v4, 0, v1
+; GFX8-NEXT:    v_max_i32_e32 v1, v4, v1
+; GFX8-NEXT:    v_sub_i32 v4, 0, v2
+; GFX8-NEXT:    v_max_i32_e32 v2, v4, v2
+; GFX8-NEXT:    v_sub_i32 v4, 0, v3
+; GFX8-NEXT:    v_max_i32_e32 v3, v4, v3
+; GFX8-NEXT:    v_readfirstlane_b32 s0, v0
+; GFX8-NEXT:    v_readfirstlane_b32 s1, v1
+; GFX8-NEXT:    v_readfirstlane_b32 s2, v2
+; GFX8-NEXT:    v_readfirstlane_b32 s3, v3
+; GFX8-NEXT:    ; return to shader part epilog
+  %res = call <4 x i32> @llvm.abs.v4i32(<4 x i32> %arg, i1 false)
+  ret <4 x i32> %res
+}