[RISCV] Add an slli.uw pattern using zext for -riscv-experimental-rv64-legal-i32

We already had the pattern for GlobalISel. Move it over to SelectionDAG.

Author: topperc

llvm/lib/Target/RISCV/RISCVGISel.td

@@ -87,13 +87,6 @@ def : Pat<(i32 (sra GPR:$rs1, (i32 GPR:$rs2))), (SRAW GPR:$rs1, GPR:$rs2)>;
 def : Pat<(i32 (srl GPR:$rs1, (i32 GPR:$rs2))), (SRLW GPR:$rs1, GPR:$rs2)>;
 }
 
-let Predicates = [HasStdExtZba, IsRV64] in {
-// This pattern is put here due to the fact that i32 is not a legal type
-// in SDISel for RV64, which is not the case in GISel.
-def : Pat<(shl (i64 (zext i32:$rs1)), uimm5:$shamt),
-          (SLLI_UW GPR:$rs1, uimm5:$shamt)>;
-} // Predicates = [HasStdExtZba, IsRV64]
-
 // Ptr type used in patterns with GlobalISelEmitter
 def PtrVT : PtrValueTypeByHwMode<XLenVT, 0>;
 

llvm/lib/Target/RISCV/RISCVInstrInfoZb.td

@@ -847,9 +847,12 @@ def : Pat<(i32 (rotl GPR:$rs1, uimm5:$rs2)),
 } // Predicates = [HasStdExtZbbOrZbkb, IsRV64]
 
 let Predicates = [HasStdExtZba, IsRV64] in {
-def : Pat<(zext GPR:$src), (ADD_UW GPR:$src, (XLenVT X0))>;
+def : Pat<(shl (i64 (zext i32:$rs1)), uimm5:$shamt),
+          (SLLI_UW GPR:$rs1, uimm5:$shamt)>;
+
 def : Pat<(i64 (add_non_imm12 (zext GPR:$rs1), GPR:$rs2)),
           (ADD_UW GPR:$rs1, GPR:$rs2)>;
+def : Pat<(zext GPR:$src), (ADD_UW GPR:$src, (XLenVT X0))>;
 
 foreach i = {1,2,3} in {
   defvar shxadd = !cast<Instruction>("SH"#i#"ADD");

llvm/test/CodeGen/RISCV/rv64-legal-i32/rv64zba.ll

@@ -45,6 +45,33 @@ define i128 @slliuw_2(i32 signext %0, ptr %1) {
   ret i128 %5
 }
 
+define i128 @slliuw_3(i32 signext %0, ptr %1) {
+; RV64I-LABEL: slliuw_3:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi a0, a0, 1
+; RV64I-NEXT:    slli a0, a0, 32
+; RV64I-NEXT:    srli a0, a0, 32
+; RV64I-NEXT:    slli a0, a0, 4
+; RV64I-NEXT:    add a1, a1, a0
+; RV64I-NEXT:    ld a0, 0(a1)
+; RV64I-NEXT:    ld a1, 8(a1)
+; RV64I-NEXT:    ret
+;
+; RV64ZBA-LABEL: slliuw_3:
+; RV64ZBA:       # %bb.0:
+; RV64ZBA-NEXT:    addi a0, a0, 1
+; RV64ZBA-NEXT:    slli.uw a0, a0, 4
+; RV64ZBA-NEXT:    add a1, a1, a0
+; RV64ZBA-NEXT:    ld a0, 0(a1)
+; RV64ZBA-NEXT:    ld a1, 8(a1)
+; RV64ZBA-NEXT:    ret
+  %add = add i32 %0, 1
+  %3 = zext i32 %add to i64
+  %4 = getelementptr inbounds i128, ptr %1, i64 %3
+  %5 = load i128, ptr %4
+  ret i128 %5
+}
+
 define i64 @adduw(i64 %a, i64 %b) nounwind {
 ; RV64I-LABEL: adduw:
 ; RV64I:       # %bb.0: