[NoTTI] reject negative scale in addressing mode

Summary:
I noticed this bug when deubging a WIP on LSR. I wonder whether and how we
should add a regression test for this.

Test Plan: no tests failed.

Reviewers: atrick

Subscribers: hfinkel, llvm-commits

Differential Revision: http://reviews.llvm.org/D9536

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@236887 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jingyue Wu 2015-05-08 18:07:24 +00:00
parent d90099d36c
commit c417f302cb
2 changed files with 31 additions and 3 deletions

View File

@ -208,9 +208,9 @@ public:
bool isLegalAddressingMode(Type *Ty, GlobalValue *BaseGV, int64_t BaseOffset,
bool HasBaseReg, int64_t Scale) {
// Guess that reg+reg addressing is allowed. This heuristic is taken from
// the implementation of LSR.
return !BaseGV && BaseOffset == 0 && Scale <= 1;
// Guess that only reg and reg+reg addressing is allowed. This heuristic is
// taken from the implementation of LSR.
return !BaseGV && BaseOffset == 0 && (Scale == 0 || Scale == 1);
}
bool isLegalMaskedStore(Type *DataType, int Consecutive) { return false; }

View File

@ -0,0 +1,28 @@
; RUN: opt < %s -loop-reduce -S | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
declare void @foo(i8)
define void @not_addressing_mode(i8* %input, i64 %n) {
; CHECK-LABEL: @not_addressing_mode(
entry:
br label %loop
loop:
; CHECK: loop:
; CHECK: %lsr.iv = phi i8* [ {{%[^,]+}}, %loop ], [ %input, %entry ]
%i = phi i64 [ 0, %entry ], [ %i.next, %loop ]
%i.next = add i64 %i, 1
%j = mul i64 %i, -2
; (%input - 2 * %j) is not foldable. Worth another indvar.
%p = getelementptr i8, i8* %input, i64 %j
%v = load i8, i8* %p
; CHECK: %v = load i8, i8* %lsr.iv
call void @foo(i8 %v)
%exitcond = icmp slt i64 %i.next, %n
br i1 %exitcond, label %exit, label %loop
exit:
ret void
}