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author | Evan Cheng <evan.cheng@apple.com> | 2008-09-04 22:59:58 +0000 |
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committer | Evan Cheng <evan.cheng@apple.com> | 2008-09-04 22:59:58 +0000 |
commit | 4a03775777785ef758cff8c0699a6bf571a1f2b9 (patch) | |
tree | a3e8d527e079840bf5627f2e68f73f901728eb1e /lib/Target/X86/X86CallingConv.td | |
parent | deafefabae915cf20884fd829d2542f9626786e8 (diff) | |
download | llvm-4a03775777785ef758cff8c0699a6bf571a1f2b9.tar.gz llvm-4a03775777785ef758cff8c0699a6bf571a1f2b9.tar.bz2 llvm-4a03775777785ef758cff8c0699a6bf571a1f2b9.tar.xz |
For whatever the reason, x86 CallingConv::Fast (i.e. fastcc) was not passing scalar arguments in registers. This patch defines a new fastcc CC which is slightly different from the FastCall CC. In addition to passing integer arguments in ECX and EDX, it also specify doubles are passed in 8-byte slots which are 8-byte aligned (instead of 4-byte aligned). This avoids a potential performance hazard where doubles span cacheline boundaries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55807 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86CallingConv.td')
-rw-r--r-- | lib/Target/X86/X86CallingConv.td | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/lib/Target/X86/X86CallingConv.td b/lib/Target/X86/X86CallingConv.td index 32f53ab8b1..549eb9b9a2 100644 --- a/lib/Target/X86/X86CallingConv.td +++ b/lib/Target/X86/X86CallingConv.td @@ -341,3 +341,20 @@ def CC_X86_32_FastCall : CallingConv<[ // Otherwise, same as everything else. CCDelegateTo<CC_X86_32_Common> ]>; + +def CC_X86_32_FastCC : CallingConv<[ + // Promote i8/i16 arguments to i32. + CCIfType<[i8, i16], CCPromoteToType<i32>>, + + // The 'nest' parameter, if any, is passed in EAX. + CCIfNest<CCAssignToReg<[EAX]>>, + + // The first 2 integer arguments are passed in ECX/EDX + CCIfType<[i32], CCAssignToReg<[ECX, EDX]>>, + + // Doubles get 8-byte slots that are 8-byte aligned. + CCIfType<[f64], CCAssignToStack<8, 8>>, + + // Otherwise, same as everything else. + CCDelegateTo<CC_X86_32_Common> +]>; |