AMDGPU: Prepare to use scalar register indexing

Define pseudos mirroring the the VGPR indexing ones, and adjust the
operands in the s_movrel* instructions to avoid the result def.

Author: arsenm

llvm/lib/Target/AMDGPU/SIInstructions.td

@@ -513,6 +513,8 @@ def ADJCALLSTACKDOWN : SPseudoInstSI<
 let Defs = [M0, EXEC, SCC],
   UseNamedOperandTable = 1 in {
 
+// SI_INDIRECT_SRC/DST are only used by legacy SelectionDAG indirect
+// addressing implementation.
 class SI_INDIRECT_SRC<RegisterClass rc> : VPseudoInstSI <
   (outs VGPR_32:$vdst),
   (ins rc:$src, VS_32:$idx, i32imm:$offset)> {
@@ -526,7 +528,6 @@ class SI_INDIRECT_DST<RegisterClass rc> : VPseudoInstSI <
   let usesCustomInserter = 1;
 }
 
-// TODO: We can support indirect SGPR access.
 def SI_INDIRECT_SRC_V1 : SI_INDIRECT_SRC<VGPR_32>;
 def SI_INDIRECT_SRC_V2 : SI_INDIRECT_SRC<VReg_64>;
 def SI_INDIRECT_SRC_V4 : SI_INDIRECT_SRC<VReg_128>;
@@ -541,6 +542,65 @@ def SI_INDIRECT_DST_V16 : SI_INDIRECT_DST<VReg_512>;
 
 } // End Uses = [EXEC], Defs = [M0, EXEC]
 
+
+// This is a pseudo variant of the v_movreld_b32 (or v_mov_b32
+// expecting to be executed with gpr indexing mode enabled)
+// instruction in which the vector operand appears only twice, once as
+// def and once as use. Using this pseudo avoids problems with the Two
+// Address instructions pass.
+class INDIRECT_REG_WRITE_pseudo<RegisterClass rc,
+                                RegisterOperand val_ty> : PseudoInstSI <
+  (outs rc:$vdst), (ins rc:$vsrc, val_ty:$val, i32imm:$subreg)> {
+  let Constraints = "$vsrc = $vdst";
+  let Uses = [M0];
+}
+
+class V_INDIRECT_REG_WRITE_B32_pseudo<RegisterClass rc> :
+  INDIRECT_REG_WRITE_pseudo<rc, VSrc_b32> {
+  let VALU = 1;
+  let VOP1 = 1;
+  let Uses = [M0, EXEC];
+}
+
+class S_INDIRECT_REG_WRITE_pseudo<RegisterClass rc,
+                                  RegisterOperand val_ty> :
+  INDIRECT_REG_WRITE_pseudo<rc, val_ty> {
+  let SALU = 1;
+  let SOP1 = 1;
+  let Uses = [M0];
+}
+
+class S_INDIRECT_REG_WRITE_B32_pseudo<RegisterClass rc> :
+  S_INDIRECT_REG_WRITE_pseudo<rc, SSrc_b32>;
+class S_INDIRECT_REG_WRITE_B64_pseudo<RegisterClass rc> :
+  S_INDIRECT_REG_WRITE_pseudo<rc, SSrc_b64>;
+
+
+def V_INDIRECT_REG_WRITE_B32_V1 : V_INDIRECT_REG_WRITE_B32_pseudo<VGPR_32>;
+def V_INDIRECT_REG_WRITE_B32_V2 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_64>;
+def V_INDIRECT_REG_WRITE_B32_V3 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_96>;
+def V_INDIRECT_REG_WRITE_B32_V4 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_128>;
+def V_INDIRECT_REG_WRITE_B32_V5 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_160>;
+def V_INDIRECT_REG_WRITE_B32_V8 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_256>;
+def V_INDIRECT_REG_WRITE_B32_V16 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_512>;
+def V_INDIRECT_REG_WRITE_B32_V32 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_1024>;
+
+def S_INDIRECT_REG_WRITE_B32_V1 : S_INDIRECT_REG_WRITE_B32_pseudo<SReg_32>;
+def S_INDIRECT_REG_WRITE_B32_V2 : S_INDIRECT_REG_WRITE_B32_pseudo<SReg_64>;
+def S_INDIRECT_REG_WRITE_B32_V3 : S_INDIRECT_REG_WRITE_B32_pseudo<SReg_96>;
+def S_INDIRECT_REG_WRITE_B32_V4 : S_INDIRECT_REG_WRITE_B32_pseudo<SReg_128>;
+def S_INDIRECT_REG_WRITE_B32_V5 : S_INDIRECT_REG_WRITE_B32_pseudo<SReg_160>;
+def S_INDIRECT_REG_WRITE_B32_V8 : S_INDIRECT_REG_WRITE_B32_pseudo<SReg_256>;
+def S_INDIRECT_REG_WRITE_B32_V16 : S_INDIRECT_REG_WRITE_B32_pseudo<SReg_512>;
+def S_INDIRECT_REG_WRITE_B32_V32 : S_INDIRECT_REG_WRITE_B32_pseudo<SReg_1024>;
+
+def S_INDIRECT_REG_WRITE_B64_V1 : S_INDIRECT_REG_WRITE_B64_pseudo<SReg_64>;
+def S_INDIRECT_REG_WRITE_B64_V2 : S_INDIRECT_REG_WRITE_B64_pseudo<SReg_128>;
+def S_INDIRECT_REG_WRITE_B64_V4 : S_INDIRECT_REG_WRITE_B64_pseudo<SReg_256>;
+def S_INDIRECT_REG_WRITE_B64_V8 : S_INDIRECT_REG_WRITE_B64_pseudo<SReg_512>;
+def S_INDIRECT_REG_WRITE_B64_V16 : S_INDIRECT_REG_WRITE_B64_pseudo<SReg_1024>;
+
+
 multiclass SI_SPILL_SGPR <RegisterClass sgpr_class> {
   let UseNamedOperandTable = 1, SGPRSpill = 1, Uses = [EXEC] in {
     def _SAVE : PseudoInstSI <

llvm/lib/Target/AMDGPU/SOPInstructions.td

@@ -97,6 +97,17 @@ class SOP1_0_32 <string opName, list<dag> pattern = []> : SOP1_Pseudo <
   let has_sdst = 0;
 }
 
+// Special case for movreld where sdst is treated as a use operand.
+class SOP1_32_movreld <string opName, list<dag> pattern=[]> : SOP1_Pseudo <
+  opName, (outs), (ins SReg_32:$sdst, SSrc_b32:$src0),
+  "$sdst, $src0", pattern>;
+
+// Special case for movreld where sdst is treated as a use operand.
+class SOP1_64_movreld <string opName, list<dag> pattern=[]> : SOP1_Pseudo <
+  opName, (outs), (ins SReg_64:$sdst, SSrc_b64:$src0),
+  "$sdst, $src0", pattern
+>;
+
 class SOP1_0_32R <string opName, list<dag> pattern = []> : SOP1_Pseudo <
   opName, (outs), (ins SReg_32:$src0),
   "$src0", pattern> {
@@ -267,8 +278,8 @@ def S_QUADMASK_B64 : SOP1_64 <"s_quadmask_b64">;
 let Uses = [M0] in {
 def S_MOVRELS_B32 : SOP1_32R <"s_movrels_b32">;
 def S_MOVRELS_B64 : SOP1_64R <"s_movrels_b64">;
-def S_MOVRELD_B32 : SOP1_32 <"s_movreld_b32">;
-def S_MOVRELD_B64 : SOP1_64 <"s_movreld_b64">;
+def S_MOVRELD_B32 : SOP1_32_movreld <"s_movreld_b32">;
+def S_MOVRELD_B64 : SOP1_64_movreld <"s_movreld_b64">;
 } // End Uses = [M0]
 
 let SubtargetPredicate = isGFX6GFX7GFX8GFX9 in {

llvm/lib/Target/AMDGPU/VOP1Instructions.td

@@ -812,29 +812,6 @@ def V_MOV_B32_indirect : VPseudoInstSI<(outs),
   let SubtargetPredicate = isGFX8GFX9;
 }
 
-// This is a pseudo variant of the v_movreld_b32 (or v_mov_b32
-// expecting to be executed with gpr indexing mode enabled)
-// instruction in which the vector operand appears only twice, once as
-// def and once as use. Using this pseudo avoids problems with the Two
-// Address instructions pass.
-class V_INDIRECT_REG_WRITE_B32_pseudo<RegisterClass rc> : VPseudoInstSI <
-  (outs rc:$vdst),
-  (ins rc:$vsrc, VSrc_b32:$val, i32imm:$subreg)> {
-  let VOP1 = 1;
-
-  let Constraints = "$vsrc = $vdst";
-  let Uses = [M0, EXEC];
-}
-
-def V_INDIRECT_REG_WRITE_B32_V1 : V_INDIRECT_REG_WRITE_B32_pseudo<VGPR_32>;
-def V_INDIRECT_REG_WRITE_B32_V2 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_64>;
-def V_INDIRECT_REG_WRITE_B32_V3 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_96>;
-def V_INDIRECT_REG_WRITE_B32_V4 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_128>;
-def V_INDIRECT_REG_WRITE_B32_V5 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_160>;
-def V_INDIRECT_REG_WRITE_B32_V8 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_256>;
-def V_INDIRECT_REG_WRITE_B32_V16 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_512>;
-def V_INDIRECT_REG_WRITE_B32_V32 : V_INDIRECT_REG_WRITE_B32_pseudo<VReg_1024>;
-
 let OtherPredicates = [isGFX8Plus] in {
 
 def : GCNPat <

llvm/test/CodeGen/AMDGPU/inserted-wait-states.mir

@@ -422,12 +422,12 @@ body: |
 
   bb.2:
     $m0 = S_MOV_B32 0
-    $sgpr0 = S_MOVRELD_B32 $sgpr0, implicit $m0
+    S_MOVRELD_B32 $sgpr0, $sgpr0, implicit $m0
     S_BRANCH %bb.3
 
   bb.3:
     $m0 = S_MOV_B32 0
-    $sgpr0_sgpr1 = S_MOVRELD_B64 $sgpr0_sgpr1, implicit $m0
+    S_MOVRELD_B64 $sgpr0_sgpr1, $sgpr0_sgpr1, implicit $m0
     S_ENDPGM 0
 ...