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| author | Evan Cheng <evan.cheng@apple.com> | 2006-12-05 03:58:23 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2006-12-05 03:58:23 +0000 |
| commit | d9ff60b955022954101700f867dcf315ba7d818d (patch) | |
| tree | 4820ca786cf503b7ac8b35e30e181221ca6092c0 /lib/Target/X86/README-X86-64.txt | |
| parent | 57c699381bfde5f8d47079cd87e4f3e7fb9fca84 (diff) | |
Update
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32214 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/README-X86-64.txt')
| -rw-r--r-- | lib/Target/X86/README-X86-64.txt | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/lib/Target/X86/README-X86-64.txt b/lib/Target/X86/README-X86-64.txt index af3e273237..a0ed3a3194 100644 --- a/lib/Target/X86/README-X86-64.txt +++ b/lib/Target/X86/README-X86-64.txt @@ -252,6 +252,16 @@ Note, however, we should continue to use RIP relative addressing mode as much as possible. The above is actually one byte shorter than movq $_dst, _ptr +A better example is the code from PR1018. We are generating: + leaq xcalloc2(%rip), %rax + movq %rax, 8(%rsp) +when we should be generating: + movq $xcalloc2, 8(%rsp) + +The reason the better codegen isn't done now is support for static small +code model in JIT mode. The JIT cannot ensure that all GV's are placed in the +lower 4G so we are not treating GV labels as 32-bit values. + //===---------------------------------------------------------------------===// Right now the asm printer assumes GlobalAddress are accessed via RIP relative |