[RISCV] Add test cases to check that we use (smax X, (neg X)) for abs with Zbb extension.

llvm/test/CodeGen/RISCV/rv32Zbb.ll

@@ -1194,3 +1194,67 @@ define i64 @maxu_i64(i64 %a, i64 %b) nounwind {
   %cond = select i1 %cmp, i64 %a, i64 %b
   ret i64 %cond
 }
+
+declare i32 @llvm.abs.i32(i32, i1 immarg)
+
+define i32 @abs_i32(i32 %x) {
+; RV32I-LABEL: abs_i32:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    srai a1, a0, 31
+; RV32I-NEXT:    add a0, a0, a1
+; RV32I-NEXT:    xor a0, a0, a1
+; RV32I-NEXT:    ret
+;
+; RV32IB-LABEL: abs_i32:
+; RV32IB:       # %bb.0:
+; RV32IB-NEXT:    neg a1, a0
+; RV32IB-NEXT:    max a0, a0, a1
+; RV32IB-NEXT:    ret
+;
+; RV32IBB-LABEL: abs_i32:
+; RV32IBB:       # %bb.0:
+; RV32IBB-NEXT:    neg a1, a0
+; RV32IBB-NEXT:    max a0, a0, a1
+; RV32IBB-NEXT:    ret
+  %abs = tail call i32 @llvm.abs.i32(i32 %x, i1 true)
+  ret i32 %abs
+}
+
+declare i64 @llvm.abs.i64(i64, i1 immarg)
+
+define i64 @abs_i64(i64 %x) {
+; RV32I-LABEL: abs_i64:
+; RV32I:       # %bb.0:
+; RV32I-NEXT:    bgez a1, .LBB27_2
+; RV32I-NEXT:  # %bb.1:
+; RV32I-NEXT:    snez a2, a0
+; RV32I-NEXT:    neg a0, a0
+; RV32I-NEXT:    add a1, a1, a2
+; RV32I-NEXT:    neg a1, a1
+; RV32I-NEXT:  .LBB27_2:
+; RV32I-NEXT:    ret
+;
+; RV32IB-LABEL: abs_i64:
+; RV32IB:       # %bb.0:
+; RV32IB-NEXT:    bgez a1, .LBB27_2
+; RV32IB-NEXT:  # %bb.1:
+; RV32IB-NEXT:    snez a2, a0
+; RV32IB-NEXT:    neg a0, a0
+; RV32IB-NEXT:    add a1, a1, a2
+; RV32IB-NEXT:    neg a1, a1
+; RV32IB-NEXT:  .LBB27_2:
+; RV32IB-NEXT:    ret
+;
+; RV32IBB-LABEL: abs_i64:
+; RV32IBB:       # %bb.0:
+; RV32IBB-NEXT:    bgez a1, .LBB27_2
+; RV32IBB-NEXT:  # %bb.1:
+; RV32IBB-NEXT:    snez a2, a0
+; RV32IBB-NEXT:    neg a0, a0
+; RV32IBB-NEXT:    add a1, a1, a2
+; RV32IBB-NEXT:    neg a1, a1
+; RV32IBB-NEXT:  .LBB27_2:
+; RV32IBB-NEXT:    ret
+  %abs = tail call i64 @llvm.abs.i64(i64 %x, i1 true)
+  ret i64 %abs
+}

llvm/test/CodeGen/RISCV/rv64Zbb.ll

@@ -949,6 +949,59 @@ define i64 @maxu_i64(i64 %a, i64 %b) nounwind {
   ret i64 %cond
 }
 
+declare i32 @llvm.abs.i32(i32, i1 immarg)
+
+define i32 @abs_i32(i32 %x) {
+; RV64I-LABEL: abs_i32:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    sext.w a0, a0
+; RV64I-NEXT:    srai a1, a0, 63
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    xor a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64IB-LABEL: abs_i32:
+; RV64IB:       # %bb.0:
+; RV64IB-NEXT:    sext.w a0, a0
+; RV64IB-NEXT:    neg a1, a0
+; RV64IB-NEXT:    max a0, a0, a1
+; RV64IB-NEXT:    ret
+;
+; RV64IBB-LABEL: abs_i32:
+; RV64IBB:       # %bb.0:
+; RV64IBB-NEXT:    sext.w a0, a0
+; RV64IBB-NEXT:    neg a1, a0
+; RV64IBB-NEXT:    max a0, a0, a1
+; RV64IBB-NEXT:    ret
+  %abs = tail call i32 @llvm.abs.i32(i32 %x, i1 true)
+  ret i32 %abs
+}
+
+declare i64 @llvm.abs.i64(i64, i1 immarg)
+
+define i64 @abs_i64(i64 %x) {
+; RV64I-LABEL: abs_i64:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    srai a1, a0, 63
+; RV64I-NEXT:    add a0, a0, a1
+; RV64I-NEXT:    xor a0, a0, a1
+; RV64I-NEXT:    ret
+;
+; RV64IB-LABEL: abs_i64:
+; RV64IB:       # %bb.0:
+; RV64IB-NEXT:    neg a1, a0
+; RV64IB-NEXT:    max a0, a0, a1
+; RV64IB-NEXT:    ret
+;
+; RV64IBB-LABEL: abs_i64:
+; RV64IBB:       # %bb.0:
+; RV64IBB-NEXT:    neg a1, a0
+; RV64IBB-NEXT:    max a0, a0, a1
+; RV64IBB-NEXT:    ret
+  %abs = tail call i64 @llvm.abs.i64(i64 %x, i1 true)
+  ret i64 %abs
+}
+
 ; We select a i32 addi that zero-extends the result on RV64 as addiwu
 
 define zeroext i32 @zext_add_to_addiwu(i32 signext %a) nounwind {