e0919b189b
RegAllocGreedy uses SlotIndexes::getApproxInstrDistance to approximate the length of a live range for its heuristics. Renumbering all slot indexes with the default instruction distance ensures that this estimate will be as accurate as possible, and will not depend on the history of how instructions have been added to and removed from SlotIndexes's maps. This also means that enabling -early-live-intervals, which runs the SlotIndexes analysis earlier, will not cause large amounts of churn due to different register allocator decisions.
70 lines
2.0 KiB
LLVM
70 lines
2.0 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
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; RUN: llc -O3 < %s -aarch64-enable-atomic-cfg-tidy=0 -aarch64-enable-gep-opt=false -verify-machineinstrs | FileCheck %s
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target triple = "arm64-apple-ios"
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; rdar://12462006
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; CSE between "icmp reg reg" and "sub reg reg".
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; Both can be in the same basic block or in different basic blocks.
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define ptr @t1(ptr %base, ptr nocapture %offset, i32 %size) nounwind {
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; CHECK-LABEL: t1:
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; CHECK: ; %bb.0: ; %entry
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; CHECK-NEXT: ldr w8, [x1]
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; CHECK-NEXT: subs w9, w8, w2
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; CHECK-NEXT: b.ge LBB0_2
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; CHECK-NEXT: ; %bb.1:
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; CHECK-NEXT: mov x0, xzr
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; CHECK-NEXT: ret
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; CHECK-NEXT: LBB0_2: ; %if.end
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; CHECK-NEXT: add x0, x0, w9, sxtw
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; CHECK-NEXT: sub w8, w8, w9
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; CHECK-NEXT: str w8, [x1]
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; CHECK-NEXT: ret
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entry:
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%0 = load i32, ptr %offset, align 4
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%cmp = icmp slt i32 %0, %size
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%s = sub nsw i32 %0, %size
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br i1 %cmp, label %return, label %if.end
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if.end:
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%sub = sub nsw i32 %0, %size
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%s2 = sub nsw i32 %s, %size
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%s3 = sub nsw i32 %sub, %s2
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store i32 %s3, ptr %offset, align 4
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%add.ptr = getelementptr inbounds i8, ptr %base, i32 %sub
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br label %return
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return:
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%retval.0 = phi ptr [ %add.ptr, %if.end ], [ null, %entry ]
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ret ptr %retval.0
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}
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; CSE between "icmp reg imm" and "sub reg imm".
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define ptr @t2(ptr %base, ptr nocapture %offset) nounwind {
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; CHECK-LABEL: t2:
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; CHECK: ; %bb.0: ; %entry
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; CHECK-NEXT: ldr w8, [x1]
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; CHECK-NEXT: subs w8, w8, #1
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; CHECK-NEXT: b.lt LBB1_2
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; CHECK-NEXT: ; %bb.1: ; %if.end
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; CHECK-NEXT: add x0, x0, w8, sxtw
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; CHECK-NEXT: str w8, [x1]
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; CHECK-NEXT: ret
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; CHECK-NEXT: LBB1_2:
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; CHECK-NEXT: mov x0, xzr
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; CHECK-NEXT: ret
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entry:
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%0 = load i32, ptr %offset, align 4
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%cmp = icmp slt i32 %0, 1
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br i1 %cmp, label %return, label %if.end
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if.end:
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%sub = sub nsw i32 %0, 1
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store i32 %sub, ptr %offset, align 4
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%add.ptr = getelementptr inbounds i8, ptr %base, i32 %sub
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br label %return
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return:
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%retval.0 = phi ptr [ %add.ptr, %if.end ], [ null, %entry ]
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ret ptr %retval.0
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}
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