[RISCV] Add test showing the current extern_weak lowering

[MaskRay]

LGTM.

[jrtc27]

Rebased

[jrtc27]

Rebased

[MaskRay]

llvm/test/CodeGen/RISCV/codemodel-lowering.ll

167

[jrtc27]

Switch to opaque pointer in test

[jrtc27]

llvm/test/CodeGen/RISCV/codemodel-lowering.ll

167

Huh, surprised that doesn't hit an error in the IR parser

[MaskRay]

Thanks!

[asb]

LGTM.

llvm/test/CodeGen/RISCV/codemodel-lowering.ll

 ; RV32I-MEDIUM-NEXT:    flw ft0, 0(a1)
 ; RV32I-MEDIUM-NEXT:    fmv.w.x ft1, a0
 ; RV32I-MEDIUM-NEXT:    fadd.s ft0, ft1, ft0
 ; RV32I-MEDIUM-NEXT:    fmv.x.w a0, ft0
 ; RV32I-MEDIUM-NEXT:    ret
   %1 = fadd float %a, 1.0
   ret float %1
 }
+
+; Check lowering of extern_weaks
+@W = extern_weak global i32
+
+define i32 @lower_extern_weak(i32 %a) nounwind {
+; RV32I-SMALL-LABEL: lower_extern_weak:
+; RV32I-SMALL:       # %bb.0:
+; RV32I-SMALL-NEXT:    lui a0, %hi(W)
+; RV32I-SMALL-NEXT:    lw a0, %lo(W)(a0)
+; RV32I-SMALL-NEXT:    ret
+;
+; RV32I-MEDIUM-LABEL: lower_extern_weak:
+; RV32I-MEDIUM:       # %bb.0:
+; RV32I-MEDIUM-NEXT:  .LBB4_1: # Label of block must be emitted
+; RV32I-MEDIUM-NEXT:    auipc a0, %pcrel_hi(W)
+; RV32I-MEDIUM-NEXT:    addi a0, a0, %pcrel_lo(.LBB4_1)
+; RV32I-MEDIUM-NEXT:    lw a0, 0(a0)
+; RV32I-MEDIUM-NEXT:    ret
+  %1 = load volatile i32, i32* @W
+  ret i32 %1
+}