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| author | Evan Cheng <evan.cheng@apple.com> | 2009-07-11 07:08:13 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2009-07-11 07:08:13 +0000 |
| commit | 2f297df02eac140de4e2f85e56bd79abf883360c (patch) | |
| tree | 94072591801953668c423bad869f1a856e213c8b /lib/Target/ARM/README-Thumb.txt | |
| parent | 446c428bf394b7113b0f18cbacb5e87b4efd1e14 (diff) | |
| download | llvm-2f297df02eac140de4e2f85e56bd79abf883360c.tar.gz llvm-2f297df02eac140de4e2f85e56bd79abf883360c.tar.bz2 llvm-2f297df02eac140de4e2f85e56bd79abf883360c.tar.xz | |
Smarter isel of ldrsb / ldrsh. Only make use of these when [r,r] address is feasible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75360 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/ARM/README-Thumb.txt')
| -rw-r--r-- | lib/Target/ARM/README-Thumb.txt | 9 |
1 files changed, 0 insertions, 9 deletions
diff --git a/lib/Target/ARM/README-Thumb.txt b/lib/Target/ARM/README-Thumb.txt index 8ffe0b17a5..cc017945d8 100644 --- a/lib/Target/ARM/README-Thumb.txt +++ b/lib/Target/ARM/README-Thumb.txt @@ -244,12 +244,3 @@ to toggle the 's' bit since they do not set CPSR when they are inside IT blocks. Make use of hi register variants of cmp: tCMPhir / tCMPZhir. //===---------------------------------------------------------------------===// - -Rather than generating ldrsb, sometimes it's better to select to ldrb + sxtb. -The problem is ldrsb addressing mode [r, r] means the zero offset requires an -extra move. e.g. ldr_ext.ll test3: - movs r1, #0 - ldrsb r0, [r0, r1] -=> - ldrb r0, [r0, #0] - sxtb r0, r0 |