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Disable the "call to immediate" optimization on x86-64. It is 

not safe in general because the immediate could be an arbitrary
value that does not fit in a 32-bit pcrel displacement.  
Conservatively fall back to loading the value into a register
and calling through it.

We still do the optzn on X86-32.

llvm-svn: 67142
This commit is contained in:
Chris Lattner 2009-03-18 00:43:52 +00:00
parent 6bfde496ee
commit a6bed3e950
2 changed files with 12 additions and 4 deletions
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6
llvm/lib/Target/X86/X86Instr64bit.td
View File

@ -109,9 +109,13 @@ let isCall = 1 in
XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7,
XMM8, XMM9, XMM10, XMM11, XMM12, XMM13, XMM14, XMM15, EFLAGS],
Uses = [RSP] in {
// NOTE: this pattern doesn't match "X86call imm", because we do not know
// that the offset between an arbitrary immediate and the call will fit in
// the 32-bit pcrel field that we have.
def CALL64pcrel32 : I<0xE8, RawFrm,
(outs), (ins i64i32imm:$dst, variable_ops),
"call\t${dst:call}", [(X86call imm:$dst)]>,
"call\t${dst:call}", []>,
Requires<[In64BitMode]>;
def CALL64r : I<0xFF, MRM2r, (outs), (ins GR64:$dst, variable_ops),
"call\t{*}$dst", [(X86call GR64:$dst)]>;

10
llvm/test/CodeGen/X86/call-imm.ll
View File

@ -1,6 +1,10 @@
; RUN: llvm-as < %s | llc -march=x86 | grep call | not grep {*}
; RUN: llvm-as < %s | llc -march=x86 | grep call | grep 12345678
; RUN: llvm-as < %s | llc -march=x86-64 | grep call | grep 12345678
; RUN: llvm-as < %s | llc -march=x86 | grep {call.*12345678}
; Call to immediate is not safe on x86-64 unless we *know* that the
; call will be within 32-bits pcrel from the dest immediate.
; RUN: llvm-as < %s | llc -march=x86-64 | grep {call.*\*%rax}
; PR3666
; PR3773