36cb33bbca
The patch add branch hint for AtomicExpandImpl::expandAtomicCmpXchg, For
example: in PowerPC, it support branch hint as
```
loop:
lwarx r6,0,r3 # load and reserve
cmpw r4,r6 #1st 2 operands equal? bne- exit #skip if not
bne- exit #skip if not
stwcx. r5,0,r3 #store new value if still res’ved bne- loop #loop if lost reservation
bne- loop #loop if lost reservation
exit:
mr r4,r6 #return value from storage
```
`-` hints not taken,
`+` hints taken,
23 lines
765 B
LLVM
23 lines
765 B
LLVM
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
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; RUN: llc -mtriple=powerpc64le-linux-gnu < %s | FileCheck %s -check-prefix=PPC64LE
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define void @test(ptr %ptr, i8 %cmp, i8 %val) {
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; PPC64LE-LABEL: test:
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; PPC64LE: # %bb.0:
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; PPC64LE-NEXT: clrlwi 5, 5, 24
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; PPC64LE-NEXT: clrlwi 4, 4, 24
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; PPC64LE-NEXT: .LBB0_1: # %cmpxchg.start
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; PPC64LE-NEXT: #
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; PPC64LE-NEXT: lbarx 6, 0, 3
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; PPC64LE-NEXT: cmplw 6, 4
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; PPC64LE-NEXT: bnelr- 0
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; PPC64LE-NEXT: # %bb.2: # %cmpxchg.fencedstore
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; PPC64LE-NEXT: #
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; PPC64LE-NEXT: stbcx. 5, 0, 3
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; PPC64LE-NEXT: bne- 0, .LBB0_1
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; PPC64LE-NEXT: # %bb.3: # %cmpxchg.end
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; PPC64LE-NEXT: blr
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%res = cmpxchg ptr %ptr, i8 %cmp, i8 %val monotonic monotonic
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ret void
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}
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