[RISCV] Add tests for merging base offset of BlockAddress

[wangpc]

Summary

We can get BlockAddress in user code via Labels as Values.

[wangpc]

Ping.

[craig.topper]

LGTM

llvm/test/CodeGen/RISCV/fold-addi-loadstore.ll

 ; RV64I-MEDIUM-NEXT:    auipc a0, %pcrel_hi(ga_16+8)
 ; RV64I-MEDIUM-NEXT:    ld a0, %pcrel_lo(.Lpcrel_hi11)(a0)
 ; RV64I-MEDIUM-NEXT:    ret
 entry:
   %0 = load i64, ptr getelementptr inbounds ([2 x i64], ptr @ga_16, i32 0, i32 1)
   ret i64 %0
 }
 
+; Check for folds in accesses to block address.
+define dso_local ptr @load_ba_1() nounwind {
+; RV32I-LABEL: load_ba_1:
+; RV32I:       # %bb.0: # %entry
+; RV32I-NEXT:  .Ltmp0: # Block address taken
+; RV32I-NEXT:  # %bb.1: # %label
+; RV32I-NEXT:    lui a0, %hi(.Ltmp0)
+; RV32I-NEXT:    lw a0, %lo(.Ltmp0)(a0)
+; RV32I-NEXT:    ret
+;
+; RV32I-MEDIUM-LABEL: load_ba_1:
+; RV32I-MEDIUM:       # %bb.0: # %entry
+; RV32I-MEDIUM-NEXT:  .Ltmp0: # Block address taken
+; RV32I-MEDIUM-NEXT:  # %bb.1: # %label
+; RV32I-MEDIUM-NEXT:  .Lpcrel_hi12:
+; RV32I-MEDIUM-NEXT:    auipc a0, %pcrel_hi(.Ltmp0)
+; RV32I-MEDIUM-NEXT:    addi a0, a0, %pcrel_lo(.Lpcrel_hi12)
+; RV32I-MEDIUM-NEXT:    lw a0, 0(a0)
+; RV32I-MEDIUM-NEXT:    ret
+;
+; RV64I-LABEL: load_ba_1:
+; RV64I:       # %bb.0: # %entry
+; RV64I-NEXT:  .Ltmp0: # Block address taken
+; RV64I-NEXT:  # %bb.1: # %label
+; RV64I-NEXT:    lui a0, %hi(.Ltmp0)
+; RV64I-NEXT:    ld a0, %lo(.Ltmp0)(a0)
+; RV64I-NEXT:    ret
+;
+; RV64I-MEDIUM-LABEL: load_ba_1:
+; RV64I-MEDIUM:       # %bb.0: # %entry
+; RV64I-MEDIUM-NEXT:  .Ltmp0: # Block address taken
+; RV64I-MEDIUM-NEXT:  # %bb.1: # %label
+; RV64I-MEDIUM-NEXT:  .Lpcrel_hi12:
+; RV64I-MEDIUM-NEXT:    auipc a0, %pcrel_hi(.Ltmp0)
+; RV64I-MEDIUM-NEXT:    addi a0, a0, %pcrel_lo(.Lpcrel_hi12)
+; RV64I-MEDIUM-NEXT:    ld a0, 0(a0)
+; RV64I-MEDIUM-NEXT:    ret
+entry:
+  br label %label
+label:
+  %0 = load ptr, ptr blockaddress(@load_ba_1, %label)
+  ret ptr %0
+}
+
+define dso_local ptr @load_ba_2() nounwind {
+; RV32I-LABEL: load_ba_2:
+; RV32I:       # %bb.0: # %entry
+; RV32I-NEXT:  .Ltmp1: # Block address taken
+; RV32I-NEXT:  # %bb.1: # %label
+; RV32I-NEXT:    lui a0, %hi(.Ltmp1)
+; RV32I-NEXT:    addi a0, a0, %lo(.Ltmp1)
+; RV32I-NEXT:    lw a0, 8(a0)
+; RV32I-NEXT:    ret
+;
+; RV32I-MEDIUM-LABEL: load_ba_2:
+; RV32I-MEDIUM:       # %bb.0: # %entry
+; RV32I-MEDIUM-NEXT:  .Ltmp1: # Block address taken
+; RV32I-MEDIUM-NEXT:  # %bb.1: # %label
+; RV32I-MEDIUM-NEXT:  .Lpcrel_hi13:
+; RV32I-MEDIUM-NEXT:    auipc a0, %pcrel_hi(.Ltmp1)
+; RV32I-MEDIUM-NEXT:    addi a0, a0, %pcrel_lo(.Lpcrel_hi13)
+; RV32I-MEDIUM-NEXT:    lw a0, 8(a0)
+; RV32I-MEDIUM-NEXT:    ret
+;
+; RV64I-LABEL: load_ba_2:
+; RV64I:       # %bb.0: # %entry
+; RV64I-NEXT:  .Ltmp1: # Block address taken
+; RV64I-NEXT:  # %bb.1: # %label
+; RV64I-NEXT:    lui a0, %hi(.Ltmp1)
+; RV64I-NEXT:    addi a0, a0, %lo(.Ltmp1)
+; RV64I-NEXT:    ld a0, 8(a0)
+; RV64I-NEXT:    ret
+;
+; RV64I-MEDIUM-LABEL: load_ba_2:
+; RV64I-MEDIUM:       # %bb.0: # %entry
+; RV64I-MEDIUM-NEXT:  .Ltmp1: # Block address taken
+; RV64I-MEDIUM-NEXT:  # %bb.1: # %label
+; RV64I-MEDIUM-NEXT:  .Lpcrel_hi13:
+; RV64I-MEDIUM-NEXT:    auipc a0, %pcrel_hi(.Ltmp1)
+; RV64I-MEDIUM-NEXT:    addi a0, a0, %pcrel_lo(.Lpcrel_hi13)
+; RV64I-MEDIUM-NEXT:    ld a0, 8(a0)
+; RV64I-MEDIUM-NEXT:    ret
+entry:
+  br label %label
+label:
+  %0 = load ptr, ptr getelementptr inbounds (i8, ptr blockaddress(@load_ba_2, %label), i32 8)
+  ret ptr %0
+}
+
 ; Check for folds in accesses to thread-local variables.
 
 @tl_4 = dso_local thread_local global i64 0, align 4
 @tl_8 = dso_local thread_local global i64 0, align 8
 
 define dso_local i64 @load_tl_4() nounwind {
 ; RV32I-LABEL: load_tl_4:
 ; RV32I:       # %bb.0: # %entry