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llvm-mirror/test/CodeGen/RISCV/wide-mem.ll
Luís Marques 0a0548042f [RISCV] Fold ADDIs into load/stores with nonzero offsets
We can often fold an ADDI into the offset of load/store instructions:

   (load (addi base, off1), off2) -> (load base, off1+off2)
   (store val, (addi base, off1), off2) -> (store val, base, off1+off2)

This is possible when the off1+off2 continues to fit the 12-bit immediate.
We remove the previous restriction where we would never fold the ADDIs if
the load/stores had nonzero offsets. We now do the fold the the resulting
constant still fits a 12-bit immediate, or if off1 is a variable's address
and we know based on that variable's alignment that off1+offs2 won't overflow.

Differential Revision: https://reviews.llvm.org/D79690
2020-07-06 17:32:57 +01:00

30 lines
836 B
LLVM

; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc -mtriple=riscv32 -verify-machineinstrs < %s \
; RUN: | FileCheck %s -check-prefix=RV32I
; Check load/store operations on values wider than what is natively supported
define i64 @load_i64(i64 *%a) nounwind {
; RV32I-LABEL: load_i64:
; RV32I: # %bb.0:
; RV32I-NEXT: lw a2, 0(a0)
; RV32I-NEXT: lw a1, 4(a0)
; RV32I-NEXT: mv a0, a2
; RV32I-NEXT: ret
%1 = load i64, i64* %a
ret i64 %1
}
@val64 = local_unnamed_addr global i64 2863311530, align 8
define i64 @load_i64_global() nounwind {
; RV32I-LABEL: load_i64_global:
; RV32I: # %bb.0:
; RV32I-NEXT: lui a1, %hi(val64)
; RV32I-NEXT: lw a0, %lo(val64)(a1)
; RV32I-NEXT: lw a1, %lo(val64+4)(a1)
; RV32I-NEXT: ret
%1 = load i64, i64* @val64
ret i64 %1
}