[llvm] [RISCV] Support the large code model. (PR #70308)

[Craig Topper via llvm-commits]

================
@@ -15,6 +23,45 @@ define i32 @test_call_external(i32 %a) nounwind {
 ; CHECK-NEXT:    lw ra, 12(sp) # 4-byte Folded Reload
 ; CHECK-NEXT:    addi sp, sp, 16
 ; CHECK-NEXT:    ret
+;
+; RV64I-LABEL: test_call_external:
+; RV64I:       # %bb.0:
+; RV64I-NEXT:    addi sp, sp, -16
+; RV64I-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
+; RV64I-NEXT:    call external_function
+; RV64I-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
+; RV64I-NEXT:    addi sp, sp, 16
+; RV64I-NEXT:    ret
+;
+; RV64I-SMALL-LABEL: test_call_external:
+; RV64I-SMALL:       # %bb.0:
+; RV64I-SMALL-NEXT:    addi sp, sp, -16
+; RV64I-SMALL-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
+; RV64I-SMALL-NEXT:    call external_function
+; RV64I-SMALL-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
+; RV64I-SMALL-NEXT:    addi sp, sp, 16
+; RV64I-SMALL-NEXT:    ret
+;
+; RV64I-MEDIUM-LABEL: test_call_external:
+; RV64I-MEDIUM:       # %bb.0:
+; RV64I-MEDIUM-NEXT:    addi sp, sp, -16
+; RV64I-MEDIUM-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
+; RV64I-MEDIUM-NEXT:    call external_function
+; RV64I-MEDIUM-NEXT:    ld ra, 8(sp) # 8-byte Folded Reload
+; RV64I-MEDIUM-NEXT:    addi sp, sp, 16
+; RV64I-MEDIUM-NEXT:    ret
+;
+; RV64I-LARGE-LABEL: test_call_external:
+; RV64I-LARGE:       # %bb.0:
+; RV64I-LARGE-NEXT:    addi sp, sp, -16
+; RV64I-LARGE-NEXT:    sd ra, 8(sp) # 8-byte Folded Spill
+; RV64I-LARGE-NEXT:  .Lpcrel_hi0:
+; RV64I-LARGE-NEXT:    auipc a1, %pcrel_hi(.LCPI0_0)
+; RV64I-LARGE-NEXT:    ld a1, %pcrel_lo(.Lpcrel_hi0)(a1)
+; RV64I-LARGE-NEXT:    jalr a1
----------------
topperc wrote:

Shouldn't this use `ra` so that it's seen as a call by the Return Address Predictor on cores that have it?

https://github.com/llvm/llvm-project/pull/70308