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| author | Peter Collingbourne <peter@pcc.me.uk> | 2014-12-30 20:05:19 +0000 |
|---|---|---|
| committer | Peter Collingbourne <peter@pcc.me.uk> | 2014-12-30 20:05:19 +0000 |
| commit | 7ef497b1f5758bb19ecac851a1f7918a5f029377 (patch) | |
| tree | 695cb749a4fb826f259f5b1b42e98f48605e68fa /llvm/test | |
| parent | a7ee2734cf8d7756ea134936ce6a7ae995d736c0 (diff) | |
| download | bcm5719-llvm-7ef497b1f5758bb19ecac851a1f7918a5f029377.tar.gz bcm5719-llvm-7ef497b1f5758bb19ecac851a1f7918a5f029377.zip | |
x86_64: Fix calls to __morestack under the large code model.
Under the large code model, we cannot assume that __morestack lives within
2^31 bytes of the call site, so we cannot use pc-relative addressing. We
cannot perform the call via a temporary register, as the rax register may
be used to store the static chain, and all other suitable registers may be
either callee-save or used for parameter passing. We cannot use the stack
at this point either because __morestack manipulates the stack directly.
To avoid these issues, perform an indirect call via a read-only memory
location containing the address.
This solution is not perfect, as it assumes that the .rodata section
is laid out within 2^31 bytes of each function body, but this seems to
be sufficient for JIT.
Differential Revision: http://reviews.llvm.org/D6787
llvm-svn: 225003
Diffstat (limited to 'llvm/test')
| -rw-r--r-- | llvm/test/CodeGen/X86/segmented-stacks.ll | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/llvm/test/CodeGen/X86/segmented-stacks.ll b/llvm/test/CodeGen/X86/segmented-stacks.ll index 45e157ff7c7..3e47121a380 100644 --- a/llvm/test/CodeGen/X86/segmented-stacks.ll +++ b/llvm/test/CodeGen/X86/segmented-stacks.ll @@ -1,5 +1,6 @@ ; RUN: llc < %s -mcpu=generic -mtriple=i686-linux -verify-machineinstrs | FileCheck %s -check-prefix=X32-Linux ; RUN: llc < %s -mcpu=generic -mtriple=x86_64-linux -verify-machineinstrs | FileCheck %s -check-prefix=X64-Linux +; RUN: llc < %s -mcpu=generic -mtriple=x86_64-linux -code-model=large -verify-machineinstrs | FileCheck %s -check-prefix=X64-Linux-Large ; RUN: llc < %s -mcpu=generic -mtriple=x86_64-linux-gnux32 -verify-machineinstrs | FileCheck %s -check-prefix=X32ABI ; RUN: llc < %s -mcpu=generic -mtriple=i686-darwin -verify-machineinstrs | FileCheck %s -check-prefix=X32-Darwin ; RUN: llc < %s -mcpu=generic -mtriple=x86_64-darwin -verify-machineinstrs | FileCheck %s -check-prefix=X64-Darwin @@ -57,6 +58,16 @@ define void @test_basic() #0 { ; X64-Linux-NEXT: callq __morestack ; X64-Linux-NEXT: ret +; X64-Linux-Large-LABEL: test_basic: + +; X64-Linux-Large: cmpq %fs:112, %rsp +; X64-Linux-Large-NEXT: ja .LBB0_2 + +; X64-Linux-Large: movabsq $40, %r10 +; X64-Linux-Large-NEXT: movabsq $0, %r11 +; X64-Linux-Large-NEXT: callq *__morestack_addr(%rip) +; X64-Linux-Large-NEXT: ret + ; X32ABI-LABEL: test_basic: ; X32ABI: cmpl %fs:64, %esp @@ -626,3 +637,7 @@ define void @test_nostack() #0 { } attributes #0 = { "split-stack" } + +; X64-Linux-Large: .rodata +; X64-Linux-Large-NEXT: __morestack_addr: +; X64-Linux-Large-NEXT: .quad __morestack |
