[llvm] r237153 - [Mips] Return false for isFPCloseToIncomingSP()

[Petar Jovanovic]

Author: petarj
Date: Tue May 12 12:14:05 2015
New Revision: 237153

URL: http://llvm.org/viewvc/llvm-project?rev=237153&view=rev
Log:
[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

Added:
    llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll
Modified:
    llvm/trunk/lib/Target/Mips/MipsFrameLowering.h

Modified: llvm/trunk/lib/Target/Mips/MipsFrameLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Mips/MipsFrameLowering.h?rev=237153&r1=237152&r2=237153&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Mips/MipsFrameLowering.h (original)
+++ llvm/trunk/lib/Target/Mips/MipsFrameLowering.h Tue May 12 12:14:05 2015
@@ -32,6 +32,8 @@ public:
 
   bool hasFP(const MachineFunction &MF) const override;
 
+  bool isFPCloseToIncomingSP() const override { return false; }
+
   void
   eliminateCallFramePseudoInstr(MachineFunction &MF,
                                 MachineBasicBlock &MBB,

Added: llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll?rev=237153&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll (added)
+++ llvm/trunk/test/CodeGen/Mips/emergency-spill-slot-near-fp.ll Tue May 12 12:14:05 2015
@@ -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
+}