[Mips] Return false for isFPCloseToIncomingSP()

On Mips, frame pointer points to the same side of the frame as the stack
pointer. This function is used to decide where to put register scavenging
spill slot. So far, it was put on the wrong side of the frame, and thus it
was too far away from $fp when frame was larger than 2^15 bytes.

Patch by Vladimir Radosavljevic.

http://reviews.llvm.org/D8895


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@237153 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Petar Jovanovic 2015-05-12 17:14:05 +00:00
parent e83e5d460d
commit 2c3514ae0d
2 changed files with 34 additions and 0 deletions

View File

@ -32,6 +32,8 @@ public:
bool hasFP(const MachineFunction &MF) const override;
bool isFPCloseToIncomingSP() const override { return false; }
void
eliminateCallFramePseudoInstr(MachineFunction &MF,
MachineBasicBlock &MBB,

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@ -0,0 +1,32 @@
; Check that register scavenging spill slot is close to $fp.
; RUN: llc -march=mipsel -O0 < %s | FileCheck %s
; CHECK: sw ${{.*}}, 4($fp)
; CHECK: lw ${{.*}}, 4($fp)
define i32 @main(i32 signext %argc, i8** %argv) "no-frame-pointer-elim"="true" {
entry:
%retval = alloca i32, align 4
%argc.addr = alloca i32, align 4
%argv.addr = alloca i8**, align 4
%v0 = alloca <16 x i8>, align 16
%.compoundliteral = alloca <16 x i8>, align 16
%v1 = alloca <16 x i8>, align 16
%.compoundliteral1 = alloca <16 x i8>, align 16
%unused_variable = alloca [16384 x i32], align 4
%result = alloca <16 x i8>, align 16
store i32 0, i32* %retval
store i32 %argc, i32* %argc.addr, align 4
store i8** %argv, i8*** %argv.addr, align 4
store <16 x i8> <i8 1, i8 2, i8 3, i8 4, i8 5, i8 6, i8 7, i8 8, i8 9, i8 10, i8 11, i8 12, i8 13, i8 14, i8 15, i8 16>, <16 x i8>* %.compoundliteral
%0 = load <16 x i8>, <16 x i8>* %.compoundliteral
store <16 x i8> %0, <16 x i8>* %v0, align 16
store <16 x i8> zeroinitializer, <16 x i8>* %.compoundliteral1
%1 = load <16 x i8>, <16 x i8>* %.compoundliteral1
store <16 x i8> %1, <16 x i8>* %v1, align 16
%2 = load <16 x i8>, <16 x i8>* %v0, align 16
%3 = load <16 x i8>, <16 x i8>* %v1, align 16
%mul = mul <16 x i8> %2, %3
store <16 x i8> %mul, <16 x i8>* %result, align 16
ret i32 0
}