[AMDGPU] Handle non-register operands for S_SUB/ADD_U64_PSEUDO (#86104)

This pseudo uses SSrc_b64 so it allows both an immediate or a register,
but the lowering crashed on immediate operands.

Author: Pierre-vh

llvm/lib/Target/AMDGPU/SIISelLowering.cpp

@@ -4859,8 +4859,8 @@ MachineBasicBlock *SITargetLowering::EmitInstrWithCustomInserter(
     if (Subtarget->hasScalarAddSub64()) {
       unsigned Opc = IsAdd ? AMDGPU::S_ADD_U64 : AMDGPU::S_SUB_U64;
       BuildMI(*BB, MI, DL, TII->get(Opc), Dest.getReg())
-          .addReg(Src0.getReg())
-          .addReg(Src1.getReg());
+        .add(Src0)
+        .add(Src1);
     } else {
       const SIRegisterInfo *TRI = ST.getRegisterInfo();
       const TargetRegisterClass *BoolRC = TRI->getBoolRC();

llvm/test/CodeGen/AMDGPU/add_sub_u64_pseudos.mir

@@ -0,0 +1,68 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=amdgcn -mcpu=gfx1100 -run-pass=finalize-isel -o - %s | FileCheck -check-prefix=GFX11 %s
+# RUN: llc -mtriple=amdgcn -mcpu=gfx1200 -run-pass=finalize-isel -o - %s | FileCheck -check-prefix=GFX12 %s
+
+---
+name: reg_ops
+tracksRegLiveness: true
+body: |
+  bb.0:
+    ; GFX11-LABEL: name: reg_ops
+    ; GFX11: [[DEF:%[0-9]+]]:sreg_64 = IMPLICIT_DEF
+    ; GFX11-NEXT: [[DEF1:%[0-9]+]]:sreg_64 = IMPLICIT_DEF
+    ; GFX11-NEXT: [[COPY:%[0-9]+]]:sreg_32 = COPY [[DEF]].sub0
+    ; GFX11-NEXT: [[COPY1:%[0-9]+]]:sreg_32 = COPY [[DEF]].sub1
+    ; GFX11-NEXT: [[COPY2:%[0-9]+]]:sreg_32 = COPY [[DEF1]].sub0
+    ; GFX11-NEXT: [[COPY3:%[0-9]+]]:sreg_32 = COPY [[DEF1]].sub1
+    ; GFX11-NEXT: [[S_ADD_U32_:%[0-9]+]]:sreg_32 = S_ADD_U32 [[COPY]], [[COPY2]], implicit-def $scc
+    ; GFX11-NEXT: [[S_ADDC_U32_:%[0-9]+]]:sreg_32 = S_ADDC_U32 [[COPY1]], [[COPY3]], implicit-def $scc, implicit $scc
+    ; GFX11-NEXT: [[REG_SEQUENCE:%[0-9]+]]:sreg_64 = REG_SEQUENCE [[S_ADD_U32_]], %subreg.sub0, [[S_ADDC_U32_]], %subreg.sub1
+    ;
+    ; GFX12-LABEL: name: reg_ops
+    ; GFX12: [[DEF:%[0-9]+]]:sreg_64 = IMPLICIT_DEF
+    ; GFX12-NEXT: [[DEF1:%[0-9]+]]:sreg_64 = IMPLICIT_DEF
+    ; GFX12-NEXT: [[S_ADD_U64_:%[0-9]+]]:sreg_64 = S_ADD_U64 [[DEF]], [[DEF1]]
+    %0:sreg_64 = IMPLICIT_DEF
+    %1:sreg_64 = IMPLICIT_DEF
+    %2:sreg_64 = S_ADD_U64_PSEUDO %0, %1, implicit-def $scc
+...
+
+---
+name: lhs_imm
+tracksRegLiveness: true
+body: |
+  bb.0:
+    ; GFX11-LABEL: name: lhs_imm
+    ; GFX11: [[DEF:%[0-9]+]]:sreg_64 = IMPLICIT_DEF
+    ; GFX11-NEXT: [[COPY:%[0-9]+]]:sreg_32 = COPY [[DEF]].sub0
+    ; GFX11-NEXT: [[COPY1:%[0-9]+]]:sreg_32 = COPY [[DEF]].sub1
+    ; GFX11-NEXT: [[S_ADD_U32_:%[0-9]+]]:sreg_32 = S_ADD_U32 6565, [[COPY]], implicit-def $scc
+    ; GFX11-NEXT: [[S_ADDC_U32_:%[0-9]+]]:sreg_32 = S_ADDC_U32 0, [[COPY1]], implicit-def $scc, implicit $scc
+    ; GFX11-NEXT: [[REG_SEQUENCE:%[0-9]+]]:sreg_64 = REG_SEQUENCE [[S_ADD_U32_]], %subreg.sub0, [[S_ADDC_U32_]], %subreg.sub1
+    ;
+    ; GFX12-LABEL: name: lhs_imm
+    ; GFX12: [[DEF:%[0-9]+]]:sreg_64 = IMPLICIT_DEF
+    ; GFX12-NEXT: [[S_ADD_U64_:%[0-9]+]]:sreg_64 = S_ADD_U64 6565, [[DEF]]
+    %0:sreg_64 = IMPLICIT_DEF
+    %1:sreg_64 = S_ADD_U64_PSEUDO 6565, %0, implicit-def $scc
+...
+
+---
+name: rhs_imm
+tracksRegLiveness: true
+body: |
+  bb.0:
+    ; GFX11-LABEL: name: rhs_imm
+    ; GFX11: [[DEF:%[0-9]+]]:sreg_64 = IMPLICIT_DEF
+    ; GFX11-NEXT: [[COPY:%[0-9]+]]:sreg_32 = COPY [[DEF]].sub0
+    ; GFX11-NEXT: [[COPY1:%[0-9]+]]:sreg_32 = COPY [[DEF]].sub1
+    ; GFX11-NEXT: [[S_ADD_U32_:%[0-9]+]]:sreg_32 = S_ADD_U32 [[COPY]], 6565, implicit-def $scc
+    ; GFX11-NEXT: [[S_ADDC_U32_:%[0-9]+]]:sreg_32 = S_ADDC_U32 [[COPY1]], 0, implicit-def $scc, implicit $scc
+    ; GFX11-NEXT: [[REG_SEQUENCE:%[0-9]+]]:sreg_64 = REG_SEQUENCE [[S_ADD_U32_]], %subreg.sub0, [[S_ADDC_U32_]], %subreg.sub1
+    ;
+    ; GFX12-LABEL: name: rhs_imm
+    ; GFX12: [[DEF:%[0-9]+]]:sreg_64 = IMPLICIT_DEF
+    ; GFX12-NEXT: [[S_ADD_U64_:%[0-9]+]]:sreg_64 = S_ADD_U64 [[DEF]], 6565
+    %0:sreg_64 = IMPLICIT_DEF
+    %1:sreg_64 = S_ADD_U64_PSEUDO %0, 6565, implicit-def $scc
+...