Arm supports negative strides as well, add them. This lets us compile:

CodeGen/ARM/arm-negative-stride.ll to:

LBB1_2: @bb
        str r1, [r3, -r0, lsl #2]
        add r0, r0, #1
        cmp r0, r2
        bne LBB1_2      @bb


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35609 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2007-04-03 00:13:57 +00:00
parent baf21999a9
commit b2c594f350

View File

@ -1323,7 +1323,7 @@ bool ARMTargetLowering::isLegalAddressingMode(const AddrMode &AM,
// This assumes i64 is legalized to a pair of i32. If not (i.e.
// ldrd / strd are used, then its address mode is same as i16.
// r + r
if (AM.Scale == 2)
if (AM.Scale == 1)
return true;
// r + r << imm
if (!isPowerOf2_32(AM.Scale & ~1))
@ -1422,7 +1422,9 @@ bool ARMTargetLowering::isLegalAddressScale(int64_t S, const Type *Ty) const {
case MVT::i1:
case MVT::i8:
case MVT::i32:
// Allow: r + r
if (S < 0) S = -S;
if (S == 1) return true; // Allow: r + r
// Allow: r << imm
// Allow: r + r << imm
S &= ~1;
@ -1431,7 +1433,8 @@ bool ARMTargetLowering::isLegalAddressScale(int64_t S, const Type *Ty) const {
// Note, we allow "void" uses (basically, uses that aren't loads or
// stores), because arm allows folding a scale into many arithmetic
// operations. This should be made more precise and revisited later.
if (S == 1) return true; // Allow: r + r
// Allow r << imm, but the imm has to be a multiple of two.
if (S & 1) return false;
return isPowerOf2_32(S);