Recommit "[RISCV] Use selectShiftMaskXLen ComplexPattern for isel of rotates."

This reverts commit dfe513a.

Tests have been changed to avoid the type legalization bug being
fixed in D126036.

Original commit message:
This will remove masks on the shift amount. We usually get this with
SimplifyDemandedBits in DAGCombine, but that's restricted to cases
where the AND has a single use. selectShiftMaskXLen does not have
that restriction.

Author: topperc

llvm/lib/Target/RISCV/RISCVInstrInfoZb.td

@@ -817,8 +817,8 @@ def : Pat<(xor GPR:$rs1, (not GPR:$rs2)), (XNOR GPR:$rs1, GPR:$rs2)>;
 } // Predicates = [HasStdExtZbbOrZbpOrZbkb]
 
 let Predicates = [HasStdExtZbbOrZbpOrZbkb] in {
-def : PatGprGpr<rotl, ROL>;
-def : PatGprGpr<rotr, ROR>;
+def : PatGprGpr<shiftop<rotl>, ROL>;
+def : PatGprGpr<shiftop<rotr>, ROR>;
 
 def : PatGprImm<rotr, RORI, uimmlog2xlen>;
 // There's no encoding for roli in the the 'B' extension as it can be
@@ -828,8 +828,8 @@ def : Pat<(rotl GPR:$rs1, uimmlog2xlen:$shamt),
 } // Predicates = [HasStdExtZbbOrZbpOrZbkb]
 
 let Predicates = [HasStdExtZbbOrZbpOrZbkb, IsRV64] in {
-def : PatGprGpr<riscv_rolw, ROLW>;
-def : PatGprGpr<riscv_rorw, RORW>;
+def : PatGprGpr<shiftopw<riscv_rolw>, ROLW>;
+def : PatGprGpr<shiftopw<riscv_rorw>, RORW>;
 def : PatGprImm<riscv_rorw, RORIW, uimm5>;
 def : Pat<(riscv_rolw GPR:$rs1, uimm5:$rs2),
           (RORIW GPR:$rs1, (ImmSubFrom32 uimm5:$rs2))>;

llvm/test/CodeGen/RISCV/rotl-rotr.ll

@@ -576,8 +576,7 @@ define signext i32 @rotl_32_mask_shared(i32 signext %a, i32 signext %b, i32 sign
 ;
 ; RV32ZBB-LABEL: rotl_32_mask_shared:
 ; RV32ZBB:       # %bb.0:
-; RV32ZBB-NEXT:    andi a3, a2, 31
-; RV32ZBB-NEXT:    rol a0, a0, a3
+; RV32ZBB-NEXT:    rol a0, a0, a2
 ; RV32ZBB-NEXT:    sll a1, a1, a2
 ; RV32ZBB-NEXT:    add a0, a0, a1
 ; RV32ZBB-NEXT:    ret
@@ -695,8 +694,7 @@ define signext i64 @rotl_64_mask_shared(i64 signext %a, i64 signext %b, i64 sign
 ;
 ; RV64ZBB-LABEL: rotl_64_mask_shared:
 ; RV64ZBB:       # %bb.0:
-; RV64ZBB-NEXT:    andi a3, a2, 63
-; RV64ZBB-NEXT:    rol a0, a0, a3
+; RV64ZBB-NEXT:    rol a0, a0, a2
 ; RV64ZBB-NEXT:    sll a1, a1, a2
 ; RV64ZBB-NEXT:    add a0, a0, a1
 ; RV64ZBB-NEXT:    ret
@@ -731,8 +729,7 @@ define signext i32 @rotr_32_mask_shared(i32 signext %a, i32 signext %b, i32 sign
 ;
 ; RV32ZBB-LABEL: rotr_32_mask_shared:
 ; RV32ZBB:       # %bb.0:
-; RV32ZBB-NEXT:    andi a3, a2, 31
-; RV32ZBB-NEXT:    ror a0, a0, a3
+; RV32ZBB-NEXT:    ror a0, a0, a2
 ; RV32ZBB-NEXT:    sll a1, a1, a2
 ; RV32ZBB-NEXT:    add a0, a0, a1
 ; RV32ZBB-NEXT:    ret
@@ -848,8 +845,7 @@ define signext i64 @rotr_64_mask_shared(i64 signext %a, i64 signext %b, i64 sign
 ;
 ; RV64ZBB-LABEL: rotr_64_mask_shared:
 ; RV64ZBB:       # %bb.0:
-; RV64ZBB-NEXT:    andi a3, a2, 63
-; RV64ZBB-NEXT:    ror a0, a0, a3
+; RV64ZBB-NEXT:    ror a0, a0, a2
 ; RV64ZBB-NEXT:    sll a1, a1, a2
 ; RV64ZBB-NEXT:    add a0, a0, a1
 ; RV64ZBB-NEXT:    ret