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[RISCV] A test demonstrating missed opportunity to combine addi into #67022

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Oct 3, 2023
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[RISCV] A test demonstrating missed opportunity to combine addi into #67022

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235 changes: 235 additions & 0 deletions llvm/test/CodeGen/RISCV/fold-addi-loadstore.ll
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Original file line number Diff line number Diff line change
Expand Up @@ -733,3 +733,238 @@ entry:
%0 = load i32, ptr inttoptr (i64 2147481600 to ptr)
ret i32 %0
}

%struct.S = type { i64, i64 }

define i64 @fold_addi_from_different_bb(i64 %k, i64 %n, ptr %a) nounwind {
; RV32I-LABEL: fold_addi_from_different_bb:
; RV32I: # %bb.0: # %entry
; RV32I-NEXT: addi sp, sp, -48
; RV32I-NEXT: sw ra, 44(sp) # 4-byte Folded Spill
; RV32I-NEXT: sw s0, 40(sp) # 4-byte Folded Spill
; RV32I-NEXT: sw s1, 36(sp) # 4-byte Folded Spill
; RV32I-NEXT: sw s2, 32(sp) # 4-byte Folded Spill
; RV32I-NEXT: sw s3, 28(sp) # 4-byte Folded Spill
; RV32I-NEXT: sw s4, 24(sp) # 4-byte Folded Spill
; RV32I-NEXT: sw s5, 20(sp) # 4-byte Folded Spill
; RV32I-NEXT: sw s6, 16(sp) # 4-byte Folded Spill
; RV32I-NEXT: sw s7, 12(sp) # 4-byte Folded Spill
; RV32I-NEXT: mv s0, a4
; RV32I-NEXT: mv s1, a3
; RV32I-NEXT: mv s2, a2
; RV32I-NEXT: beqz a3, .LBB20_3
; RV32I-NEXT: # %bb.1: # %entry
; RV32I-NEXT: slti a1, s1, 0
; RV32I-NEXT: beqz a1, .LBB20_4
; RV32I-NEXT: .LBB20_2:
; RV32I-NEXT: li s3, 0
; RV32I-NEXT: li s4, 0
; RV32I-NEXT: j .LBB20_6
; RV32I-NEXT: .LBB20_3:
; RV32I-NEXT: seqz a1, s2
; RV32I-NEXT: bnez a1, .LBB20_2
; RV32I-NEXT: .LBB20_4: # %for.body.lr.ph
; RV32I-NEXT: li s5, 0
; RV32I-NEXT: li s6, 0
; RV32I-NEXT: li s3, 0
; RV32I-NEXT: li s4, 0
; RV32I-NEXT: slli a0, a0, 4
; RV32I-NEXT: add a0, s0, a0
; RV32I-NEXT: addi s7, a0, 8
; RV32I-NEXT: .LBB20_5: # %for.body
; RV32I-NEXT: # =>This Inner Loop Header: Depth=1
; RV32I-NEXT: mv a0, s0
; RV32I-NEXT: call f@plt
; RV32I-NEXT: lw a0, 4(s7)
; RV32I-NEXT: lw a1, 0(s7)
; RV32I-NEXT: add a0, a0, s4
; RV32I-NEXT: add s3, a1, s3
; RV32I-NEXT: sltu s4, s3, a1
; RV32I-NEXT: addi s5, s5, 1
; RV32I-NEXT: seqz a1, s5
; RV32I-NEXT: add s6, s6, a1
; RV32I-NEXT: xor a1, s5, s2
; RV32I-NEXT: xor a2, s6, s1
; RV32I-NEXT: or a1, a1, a2
; RV32I-NEXT: add s4, a0, s4
; RV32I-NEXT: bnez a1, .LBB20_5
; RV32I-NEXT: .LBB20_6: # %for.cond.cleanup
; RV32I-NEXT: mv a0, s3
; RV32I-NEXT: mv a1, s4
; RV32I-NEXT: lw ra, 44(sp) # 4-byte Folded Reload
; RV32I-NEXT: lw s0, 40(sp) # 4-byte Folded Reload
; RV32I-NEXT: lw s1, 36(sp) # 4-byte Folded Reload
; RV32I-NEXT: lw s2, 32(sp) # 4-byte Folded Reload
; RV32I-NEXT: lw s3, 28(sp) # 4-byte Folded Reload
; RV32I-NEXT: lw s4, 24(sp) # 4-byte Folded Reload
; RV32I-NEXT: lw s5, 20(sp) # 4-byte Folded Reload
; RV32I-NEXT: lw s6, 16(sp) # 4-byte Folded Reload
; RV32I-NEXT: lw s7, 12(sp) # 4-byte Folded Reload
; RV32I-NEXT: addi sp, sp, 48
; RV32I-NEXT: ret
;
; RV32I-MEDIUM-LABEL: fold_addi_from_different_bb:
; RV32I-MEDIUM: # %bb.0: # %entry
; RV32I-MEDIUM-NEXT: addi sp, sp, -48
; RV32I-MEDIUM-NEXT: sw ra, 44(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: sw s0, 40(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: sw s1, 36(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: sw s2, 32(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: sw s3, 28(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: sw s4, 24(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: sw s5, 20(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: sw s6, 16(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: sw s7, 12(sp) # 4-byte Folded Spill
; RV32I-MEDIUM-NEXT: mv s0, a4
; RV32I-MEDIUM-NEXT: mv s1, a3
; RV32I-MEDIUM-NEXT: mv s2, a2
; RV32I-MEDIUM-NEXT: beqz a3, .LBB20_3
; RV32I-MEDIUM-NEXT: # %bb.1: # %entry
; RV32I-MEDIUM-NEXT: slti a1, s1, 0
; RV32I-MEDIUM-NEXT: beqz a1, .LBB20_4
; RV32I-MEDIUM-NEXT: .LBB20_2:
; RV32I-MEDIUM-NEXT: li s3, 0
; RV32I-MEDIUM-NEXT: li s4, 0
; RV32I-MEDIUM-NEXT: j .LBB20_6
; RV32I-MEDIUM-NEXT: .LBB20_3:
; RV32I-MEDIUM-NEXT: seqz a1, s2
; RV32I-MEDIUM-NEXT: bnez a1, .LBB20_2
; RV32I-MEDIUM-NEXT: .LBB20_4: # %for.body.lr.ph
; RV32I-MEDIUM-NEXT: li s5, 0
; RV32I-MEDIUM-NEXT: li s6, 0
; RV32I-MEDIUM-NEXT: li s3, 0
; RV32I-MEDIUM-NEXT: li s4, 0
; RV32I-MEDIUM-NEXT: slli a0, a0, 4
; RV32I-MEDIUM-NEXT: add a0, s0, a0
; RV32I-MEDIUM-NEXT: addi s7, a0, 8
; RV32I-MEDIUM-NEXT: .LBB20_5: # %for.body
; RV32I-MEDIUM-NEXT: # =>This Inner Loop Header: Depth=1
; RV32I-MEDIUM-NEXT: mv a0, s0
; RV32I-MEDIUM-NEXT: call f@plt
; RV32I-MEDIUM-NEXT: lw a0, 4(s7)
; RV32I-MEDIUM-NEXT: lw a1, 0(s7)
; RV32I-MEDIUM-NEXT: add a0, a0, s4
; RV32I-MEDIUM-NEXT: add s3, a1, s3
; RV32I-MEDIUM-NEXT: sltu s4, s3, a1
; RV32I-MEDIUM-NEXT: addi s5, s5, 1
; RV32I-MEDIUM-NEXT: seqz a1, s5
; RV32I-MEDIUM-NEXT: add s6, s6, a1
; RV32I-MEDIUM-NEXT: xor a1, s5, s2
; RV32I-MEDIUM-NEXT: xor a2, s6, s1
; RV32I-MEDIUM-NEXT: or a1, a1, a2
; RV32I-MEDIUM-NEXT: add s4, a0, s4
; RV32I-MEDIUM-NEXT: bnez a1, .LBB20_5
; RV32I-MEDIUM-NEXT: .LBB20_6: # %for.cond.cleanup
; RV32I-MEDIUM-NEXT: mv a0, s3
; RV32I-MEDIUM-NEXT: mv a1, s4
; RV32I-MEDIUM-NEXT: lw ra, 44(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: lw s0, 40(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: lw s1, 36(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: lw s2, 32(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: lw s3, 28(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: lw s4, 24(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: lw s5, 20(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: lw s6, 16(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: lw s7, 12(sp) # 4-byte Folded Reload
; RV32I-MEDIUM-NEXT: addi sp, sp, 48
; RV32I-MEDIUM-NEXT: ret
;
; RV64I-LABEL: fold_addi_from_different_bb:
; RV64I: # %bb.0: # %entry
; RV64I-NEXT: addi sp, sp, -48
; RV64I-NEXT: sd ra, 40(sp) # 8-byte Folded Spill
; RV64I-NEXT: sd s0, 32(sp) # 8-byte Folded Spill
; RV64I-NEXT: sd s1, 24(sp) # 8-byte Folded Spill
; RV64I-NEXT: sd s2, 16(sp) # 8-byte Folded Spill
; RV64I-NEXT: sd s3, 8(sp) # 8-byte Folded Spill
; RV64I-NEXT: blez a1, .LBB20_3
; RV64I-NEXT: # %bb.1: # %for.body.lr.ph
; RV64I-NEXT: mv s0, a2
; RV64I-NEXT: mv s1, a1
; RV64I-NEXT: li s2, 0
; RV64I-NEXT: slli a0, a0, 4
; RV64I-NEXT: add a0, a2, a0
; RV64I-NEXT: addi s3, a0, 8
; RV64I-NEXT: .LBB20_2: # %for.body
; RV64I-NEXT: # =>This Inner Loop Header: Depth=1
; RV64I-NEXT: mv a0, s0
; RV64I-NEXT: call f@plt
; RV64I-NEXT: ld a0, 0(s3)
; RV64I-NEXT: addi s1, s1, -1
; RV64I-NEXT: add s2, a0, s2
; RV64I-NEXT: bnez s1, .LBB20_2
; RV64I-NEXT: j .LBB20_4
; RV64I-NEXT: .LBB20_3:
; RV64I-NEXT: li s2, 0
; RV64I-NEXT: .LBB20_4: # %for.cond.cleanup
; RV64I-NEXT: mv a0, s2
; RV64I-NEXT: ld ra, 40(sp) # 8-byte Folded Reload
; RV64I-NEXT: ld s0, 32(sp) # 8-byte Folded Reload
; RV64I-NEXT: ld s1, 24(sp) # 8-byte Folded Reload
; RV64I-NEXT: ld s2, 16(sp) # 8-byte Folded Reload
; RV64I-NEXT: ld s3, 8(sp) # 8-byte Folded Reload
; RV64I-NEXT: addi sp, sp, 48
; RV64I-NEXT: ret
;
; RV64I-MEDIUM-LABEL: fold_addi_from_different_bb:
; RV64I-MEDIUM: # %bb.0: # %entry
; RV64I-MEDIUM-NEXT: addi sp, sp, -48
; RV64I-MEDIUM-NEXT: sd ra, 40(sp) # 8-byte Folded Spill
; RV64I-MEDIUM-NEXT: sd s0, 32(sp) # 8-byte Folded Spill
; RV64I-MEDIUM-NEXT: sd s1, 24(sp) # 8-byte Folded Spill
; RV64I-MEDIUM-NEXT: sd s2, 16(sp) # 8-byte Folded Spill
; RV64I-MEDIUM-NEXT: sd s3, 8(sp) # 8-byte Folded Spill
; RV64I-MEDIUM-NEXT: blez a1, .LBB20_3
; RV64I-MEDIUM-NEXT: # %bb.1: # %for.body.lr.ph
; RV64I-MEDIUM-NEXT: mv s0, a2
; RV64I-MEDIUM-NEXT: mv s1, a1
; RV64I-MEDIUM-NEXT: li s2, 0
; RV64I-MEDIUM-NEXT: slli a0, a0, 4
; RV64I-MEDIUM-NEXT: add a0, a2, a0
; RV64I-MEDIUM-NEXT: addi s3, a0, 8
; RV64I-MEDIUM-NEXT: .LBB20_2: # %for.body
; RV64I-MEDIUM-NEXT: # =>This Inner Loop Header: Depth=1
; RV64I-MEDIUM-NEXT: mv a0, s0
; RV64I-MEDIUM-NEXT: call f@plt
; RV64I-MEDIUM-NEXT: ld a0, 0(s3)
; RV64I-MEDIUM-NEXT: addi s1, s1, -1
; RV64I-MEDIUM-NEXT: add s2, a0, s2
; RV64I-MEDIUM-NEXT: bnez s1, .LBB20_2
; RV64I-MEDIUM-NEXT: j .LBB20_4
; RV64I-MEDIUM-NEXT: .LBB20_3:
; RV64I-MEDIUM-NEXT: li s2, 0
; RV64I-MEDIUM-NEXT: .LBB20_4: # %for.cond.cleanup
; RV64I-MEDIUM-NEXT: mv a0, s2
; RV64I-MEDIUM-NEXT: ld ra, 40(sp) # 8-byte Folded Reload
; RV64I-MEDIUM-NEXT: ld s0, 32(sp) # 8-byte Folded Reload
; RV64I-MEDIUM-NEXT: ld s1, 24(sp) # 8-byte Folded Reload
; RV64I-MEDIUM-NEXT: ld s2, 16(sp) # 8-byte Folded Reload
; RV64I-MEDIUM-NEXT: ld s3, 8(sp) # 8-byte Folded Reload
; RV64I-MEDIUM-NEXT: addi sp, sp, 48
; RV64I-MEDIUM-NEXT: ret
entry:
%cmp4 = icmp sgt i64 %n, 0
br i1 %cmp4, label %for.body.lr.ph, label %for.cond.cleanup

for.body.lr.ph: ; preds = %entry
; TODO: when this GEP is expanded, the resulting `addi` should be folded
; into the load in the loop body.
%y = getelementptr inbounds %struct.S, ptr %a, i64 %k, i32 1
br label %for.body

for.cond.cleanup: ; preds = %for.body, %entry
%s.0.lcssa = phi i64 [ 0, %entry ], [ %add, %for.body ]
ret i64 %s.0.lcssa

for.body: ; preds = %for.body.lr.ph, %for.body
%i.06 = phi i64 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
%s.05 = phi i64 [ 0, %for.body.lr.ph ], [ %add, %for.body ]
call void @f(ptr %a)
%0 = load i64, ptr %y, align 8
%add = add nsw i64 %0, %s.05
%inc = add nuw nsw i64 %i.06, 1
%exitcond.not = icmp eq i64 %inc, %n
br i1 %exitcond.not, label %for.cond.cleanup, label %for.body
}

declare void @f(ptr)