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[QTOOL-37352] Consider isLegalAddressingImm in Constant Hoisting

Description

[QTOOL-37352] Consider isLegalAddressingImm in Constant Hoisting

In Thumb1, legal imm range is [0, 255] for ADD/SUB instructions. However, the
legal imm range for LD/ST in (R+Imm) addressing mode is [0, 127]. Imms in
[128, 255] are materialized by mov R, #imm, and LD/STs use them in (R+R)
addressing mode.

This patch checks if a constant is used as offset in (R+Imm), if so, it checks
isLegalAddressingMode passing the constant value as BaseOffset.

Differential Revision: https://reviews.llvm.org/D50931

Details

Committed
zzhengAug 28 2018, 4:00 PM
Differential Revision
D50931: Consider isLegalAddressingImm in Constant Hoisting
Parents
rL340881: [ORC] Add a testcase for r338975.
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