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author | David Woodhouse <dwmw2@infradead.org> | 2014-01-13 14:05:59 +0000 |
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committer | David Woodhouse <dwmw2@infradead.org> | 2014-01-13 14:05:59 +0000 |
commit | f71254859e1f96944c4f4cedeecc940bce3c1e66 (patch) | |
tree | f4fbb1596fd57a432c93520b12ba7528b4bfa253 /lib/Target/X86/X86FloatingPoint.cpp | |
parent | 7f2eff792a2e18758a25956abdac2440ee18dd7f (diff) | |
download | llvm-f71254859e1f96944c4f4cedeecc940bce3c1e66.tar.gz llvm-f71254859e1f96944c4f4cedeecc940bce3c1e66.tar.bz2 llvm-f71254859e1f96944c4f4cedeecc940bce3c1e66.tar.xz |
[x86] Fix retq/retl handling in 64-bit mode
This finishes the job started in r198756, and creates separate opcodes for
64-bit vs. 32-bit versions of the rest of the RET instructions too.
LRETL/LRETQ are interesting... I can't see any justification for their
existence in the SDM. There should be no 'LRETL' in 64-bit mode, and no
need for a REX.W prefix for LRETQ. But this is what GAS does, and my
Sandybridge CPU and an Opteron 6376 concur when tested as follows:
asm __volatile__("pushq $0x1234\nmovq $0x33,%rax\nsalq $32,%rax\norq $1f,%rax\npushq %rax\nlretl $8\n1:");
asm __volatile__("pushq $1234\npushq $0x33\npushq $1f\nlretq $8\n1:");
asm __volatile__("pushq $0x33\npushq $1f\nlretq\n1:");
asm __volatile__("pushq $0x1234\npushq $0x33\npushq $1f\nlretq $8\n1:");
cf. PR8592 and commit r118903, which added LRETQ. I only added LRETIQ to
match it.
I don't quite understand how the Intel syntax parsing for ret
instructions is working, despite r154468 allegedly fixing it. Aren't the
explicitly sized 'retw', 'retd' and 'retq' supposed to work? I have at
least made the 'lretq' work with (and indeed *require*) the 'q'.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199106 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86FloatingPoint.cpp')
-rw-r--r-- | lib/Target/X86/X86FloatingPoint.cpp | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/lib/Target/X86/X86FloatingPoint.cpp b/lib/Target/X86/X86FloatingPoint.cpp index d6d0bbc1b5..c7f8514106 100644 --- a/lib/Target/X86/X86FloatingPoint.cpp +++ b/lib/Target/X86/X86FloatingPoint.cpp @@ -1673,7 +1673,8 @@ void FPS::handleSpecialFP(MachineBasicBlock::iterator &I) { case X86::RETQ: case X86::RETL: - case X86::RETI: + case X86::RETIL: + case X86::RETIQ: // If RET has an FP register use operand, pass the first one in ST(0) and // the second one in ST(1). |