diff options
| author | Tim Northover <tnorthover@apple.com> | 2016-05-05 18:38:53 +0000 |
|---|---|---|
| committer | Tim Northover <tnorthover@apple.com> | 2016-05-05 18:38:53 +0000 |
| commit | 7c4f7f326e3913a48168269198196efc9058b4b1 (patch) | |
| tree | d6aeb7e0cce9a945feedfe4d666001fcfea84df8 /test/CodeGen/ARM | |
| parent | 8cb434aecfa3f5a2515d837b2a9745da20c60c67 (diff) | |
ARM: don't attempt to merge litpools referencing different PC-anchors.
Given something like:
ldr r0, .LCPI0_0 (== pc-rel var)
add r0, pc
ldr r1, .LCPI0_1 (== pc-rel var)
add r1, pc
we cannot combine the 2 ldr instructions and litpools because they get added to
a different pc to form the correct address. I think the original logic came
from a time when we fused the LDRpci/PICADD instructions into one
pseudo-instruction so the PC was always immediately at-hand. That's no longer
the case.
Should fix general-dynamic TLS access on Linux, and quite possibly other -fPIC
code that relies on litpools (e.g. v6m and -Oz compilations) though trivial
tweaks of the .ll test didn't provoke anything.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268662 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/CodeGen/ARM')
| -rw-r--r-- | test/CodeGen/ARM/litpool-licm.ll | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/test/CodeGen/ARM/litpool-licm.ll b/test/CodeGen/ARM/litpool-licm.ll new file mode 100644 index 00000000000..dc6b37feaf0 --- /dev/null +++ b/test/CodeGen/ARM/litpool-licm.ll @@ -0,0 +1,46 @@ +; RUN: llc -mtriple=thumbv7-linux-gnueabihf -relocation-model=pic %s -o - | FileCheck %s + +@var = thread_local global i32 0, align 4 + +define void @func(i32 %n) { +; CHECK-LABEL: func: +; CHECK: ldr [[REF1:r[0-9]+]], [[CP1:.LCPI[0-9]+_[0-9]+]] +; CHECK: ldr [[REF2:r[0-9]+]], [[CP2:.LCPI[0-9]+_[0-9]+]] + +; CHECK: [[PCPOS1:.LPC[0-9]+_[0-9]+]]: +; CHECK-NEXT: add [[REF1]], pc + +; CHECK: [[PCPOS2:.LPC[0-9]+_[0-9]+]]: +; CHECK-NEXT: add [[REF2]], pc + +; CHECK: [[CP1]]: +; CHECK-NEXT: [[CP1_TMP:.Ltmp[0-9]+]]: +; CHECK-NEXT: .long var(TLSGD)-(([[PCPOS1]]+4)-[[CP1_TMP]]) + +; CHECK: [[CP2]]: +; CHECK-NEXT: [[CP2_TMP:.Ltmp[0-9]+]]: +; CHECK-NEXT: .long var(TLSGD)-(([[PCPOS2]]+4)-[[CP2_TMP]]) + +entry: + br label %loop + +loop: + %i = phi i32 [ %inc, %next ], [ 0, %entry ] + %val = load i32, i32* @var + %tst = icmp eq i32 %val, 0 + br i1 %tst, label %next, label %call + +call: + tail call void @foo(i32* nonnull @var) #2 + br label %next + +next: + %inc = add i32 %i, 1 + %stop = icmp eq i32 %inc, %n + br i1 %stop, label %done, label %loop + +done: + ret void +} + +declare void @foo(i32*)
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