Reviewers: balazs.kilvady, akos.palfi.imgtec, ilija.pavlovic_imgtec.com,
Message:
PTAL, this is first step in getting some callee-saved regs into our register
allocator list, for use in interpreter. MIPS64 port still to come.
Description:
MIPS: Tweak CEntryStub to free up callee-saved regs s0-s2.
BUG=
Please review this at https://codereview.chromium.org/1263723002/
Base URL: https://chromium.googlesource.com/v8/v8.git@master
Affected files (+13, -18 lines):
M src/mips/code-stubs-mips.cc
Index: src/mips/code-stubs-mips.cc
diff --git a/src/mips/code-stubs-mips.cc b/src/mips/code-stubs-mips.cc
index
5ebb70ed8bc6b41a73196ceb006bf8174733e854..7d3d12436eee67ea3f4f0309e11964ea309de074
100644
--- a/src/mips/code-stubs-mips.cc
+++ b/src/mips/code-stubs-mips.cc
@@ -1070,24 +1070,20 @@ void CEntryStub::Generate(MacroAssembler* masm) {
ProfileEntryHookStub::MaybeCallEntryHook(masm);
- // Compute the argv pointer in a callee-saved register.
- __ sll(s1, a0, kPointerSizeLog2);
- __ Addu(s1, sp, s1);
- __ Subu(s1, s1, kPointerSize);
+ __ mov(t9, a1); // Function pointer to t9 to conform to ABI for PIC.
+ // Compute the argv pointer in a1.
+ __ sll(a1, a0, kPointerSizeLog2);
+ __ Addu(a1, sp, a1);
+ __ Subu(a1, a1, kPointerSize);
// Enter the exit frame that transitions from JavaScript to C++.
FrameScope scope(masm, StackFrame::MANUAL);
__ EnterExitFrame(save_doubles());
- // s0: number of arguments including receiver (C callee-saved)
- // s1: pointer to first argument (C callee-saved)
- // s2: pointer to builtin function (C callee-saved)
-
- // Prepare arguments for C routine.
- // a0 = argc
- __ mov(s0, a0);
- __ mov(s2, a1);
- // a1 = argv (set in the delay slot after find_ra below).
+ // argc will be saved in s5 (callee-saved) in delay-slot of bal() below.
+ // a0, s5: number of arguments including receiver.
+ // a1: pointer to the first argument.
+ // t9: pointer to builtin function.
// We are calling compiled C/C++ code. a0 and a1 hold our two arguments.
We
// also need to reserve the 4 argument slots on the stack.
@@ -1107,20 +1103,19 @@ void CEntryStub::Generate(MacroAssembler* masm) {
// coverage code can interfere with the proper calculation of ra.
Label find_ra;
masm->bal(&find_ra); // bal exposes branch delay slot.
- masm->mov(a1, s1);
+ masm->mov(s5, a0); // Save argc for LeaveExitFrame() below.
masm->bind(&find_ra);
// Adjust the value in ra to point to the correct return location, 2nd
// instruction past the real call into C code (the jalr(t9)), and push
it.
// This is the return address of the exit frame.
- const int kNumInstructionsToJump = 5;
+ const int kNumInstructionsToJump = 4;
masm->Addu(ra, ra, kNumInstructionsToJump * kPointerSize);
masm->sw(ra, MemOperand(sp)); // This spot was reserved in
EnterExitFrame.
// Stack space reservation moved to the branch delay slot below.
// Stack is still aligned.
// Call the C routine.
- masm->mov(t9, s2); // Function pointer to t9 to conform to ABI for
PIC.
masm->jalr(t9);
// Set up sp in the delay slot.
masm->addiu(sp, sp, -kCArgsSlotsSize);
@@ -1154,8 +1149,8 @@ void CEntryStub::Generate(MacroAssembler* masm) {
// v0:v1: result
// sp: stack pointer
// fp: frame pointer
- // s0: still holds argc (callee-saved).
- __ LeaveExitFrame(save_doubles(), s0, true, EMIT_RETURN);
+ // s5: still holds argc (callee-saved).
+ __ LeaveExitFrame(save_doubles(), s5, true, EMIT_RETURN);
// Handling of exception.
__ bind(&exception_returned);
--
--
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