diff options
author | Chandler Carruth <chandlerc@gmail.com> | 2018-07-23 07:56:15 +0000 |
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committer | Chandler Carruth <chandlerc@gmail.com> | 2018-07-23 07:56:15 +0000 |
commit | 1d926fb9f4a967c7d1ef7312e147933987c8cd7b (patch) | |
tree | 01a0beab6553a673e5087264b5310b40d0ba73be | |
parent | b66f2d8df8c05328c4c478876b5ebb58564d7722 (diff) | |
download | bcm5719-llvm-1d926fb9f4a967c7d1ef7312e147933987c8cd7b.tar.gz bcm5719-llvm-1d926fb9f4a967c7d1ef7312e147933987c8cd7b.zip |
[x86/SLH] Fix a bug where we would harden tail calls twice -- once as
a call, and then again as a return.
Also added a comment to try and explain better why we would be doing
what we're doing when hardening the (non-call) returns.
llvm-svn: 337673
-rw-r--r-- | llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp | 6 | ||||
-rw-r--r-- | llvm/test/CodeGen/X86/speculative-load-hardening-indirect.ll | 6 |
2 files changed, 5 insertions, 7 deletions
diff --git a/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp b/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp index c068507095a..3d2bbd3e55c 100644 --- a/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp +++ b/llvm/lib/Target/X86/X86SpeculativeLoadHardening.cpp @@ -525,7 +525,11 @@ bool X86SpeculativeLoadHardeningPass::runOnMachineFunction( continue; MachineInstr &MI = MBB.back(); - if (!MI.isReturn()) + + // We only care about returns that are not also calls. For calls, that + // happen to also be returns (tail calls) we will have already handled + // them as calls. + if (!MI.isReturn() || MI.isCall()) continue; hardenReturnInstr(MI); diff --git a/llvm/test/CodeGen/X86/speculative-load-hardening-indirect.ll b/llvm/test/CodeGen/X86/speculative-load-hardening-indirect.ll index b067c10a254..33741ff7b75 100644 --- a/llvm/test/CodeGen/X86/speculative-load-hardening-indirect.ll +++ b/llvm/test/CodeGen/X86/speculative-load-hardening-indirect.ll @@ -37,9 +37,6 @@ define i32 @test_indirect_tail_call(i32 ()** %ptr) nounwind { ; X64-NEXT: movq %rsp, %rax ; X64-NEXT: movq $-1, %rcx ; X64-NEXT: sarq $63, %rax -; X64-NEXT: movq %rax, %rcx -; X64-NEXT: shlq $47, %rcx -; X64-NEXT: orq %rcx, %rsp ; X64-NEXT: shlq $47, %rax ; X64-NEXT: orq %rax, %rsp ; X64-NEXT: jmpq *(%rdi) # TAILCALL @@ -77,9 +74,6 @@ define i32 @test_indirect_tail_call_global() nounwind { ; X64-NEXT: movq %rsp, %rax ; X64-NEXT: movq $-1, %rcx ; X64-NEXT: sarq $63, %rax -; X64-NEXT: movq %rax, %rcx -; X64-NEXT: shlq $47, %rcx -; X64-NEXT: orq %rcx, %rsp ; X64-NEXT: shlq $47, %rax ; X64-NEXT: orq %rax, %rsp ; X64-NEXT: jmpq *{{.*}}(%rip) # TAILCALL |