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authorChris Lattner <sabre@nondot.org>2009-09-13 17:25:49 +0000
committerChris Lattner <sabre@nondot.org>2009-09-13 17:25:49 +0000
commitf6dd026fed67d7f7654f26c2bff1ef7652de2023 (patch)
tree09565cd6d412cbb401400f2abf101c969be7037a /docs/HistoricalNotes
parent39ddef30c94c737f95260f818e5f1cca560a3088 (diff)
remove two docs about the old Sparc backend which used Value*'s for vregs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81680 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/HistoricalNotes')
-rw-r--r--docs/HistoricalNotes/2001-07-08-InstructionSelection.txt51
-rw-r--r--docs/HistoricalNotes/2001-07-08-InstructionSelection2.txt25
2 files changed, 0 insertions, 76 deletions
diff --git a/docs/HistoricalNotes/2001-07-08-InstructionSelection.txt b/docs/HistoricalNotes/2001-07-08-InstructionSelection.txt
deleted file mode 100644
index 8cc75b89b8..0000000000
--- a/docs/HistoricalNotes/2001-07-08-InstructionSelection.txt
+++ /dev/null
@@ -1,51 +0,0 @@
-Date: Sun, 8 Jul 2001 09:37:22 -0500
-From: Vikram S. Adve <vadve@cs.uiuc.edu>
-To: Ruchira Sasanka <sasanka@students.uiuc.edu>
-Cc: Chris Lattner <lattner@cs.uiuc.edu>
-Subject: machine instruction operands
-
-Ruchira,
-
-When generating machine instructions, I have to make several choices about
-operands. For cases were a register is required, there are 3 cases:
-
-1. The register is for a Value* that is already in the VM code.
-
-2. The register is for a value that is not in the VM code, usually because 2
-machine instructions get generated for a single VM instruction (and the
-register holds the result of the first m/c instruction and is used by the
-second m/c instruction).
-
-3. The register is a pre-determined machine register.
-
-E.g, for this VM instruction:
- ptr = alloca type, numElements
-I have to generate 2 machine instructions:
- reg = mul constant, numElements
- ptr = add %sp, reg
-
-Each machine instruction is of class MachineInstr.
-It has a vector of operands. All register operands have type MO_REGISTER.
-The 3 types of register operands are marked using this enum:
-
- enum VirtualRegisterType {
- MO_VMVirtualReg, // virtual register for *value
- MO_MInstrVirtualReg, // virtual register for result of *minstr
- MO_MachineReg // pre-assigned machine register `regNum'
- } vregType;
-
-Here's how this affects register allocation:
-
-1. MO_VMVirtualReg is the standard case: you just do the register
-allocation.
-
-2. MO_MInstrVirtualReg is the case where there is a hidden register being
-used. You should decide how you want to handle it, e.g., do you want do
-create a Value object during the preprocessing phase to make the value
-explicit (like for address register for the RETURN instruction).
-
-3. For case MO_MachineReg, you don't need to do anything, at least for
-SPARC. The only machine regs I am using so far are %g0 and %sp.
-
---Vikram
-
diff --git a/docs/HistoricalNotes/2001-07-08-InstructionSelection2.txt b/docs/HistoricalNotes/2001-07-08-InstructionSelection2.txt
deleted file mode 100644
index 1ae006d508..0000000000
--- a/docs/HistoricalNotes/2001-07-08-InstructionSelection2.txt
+++ /dev/null
@@ -1,25 +0,0 @@
-Date: Sun, 8 Jul 2001 10:02:20 -0500
-From: Vikram S. Adve <vadve@cs.uiuc.edu>
-To: vadve@cs.uiuc.edu, Ruchira Sasanka <sasanka@students.uiuc.edu>
-Cc: Chris Lattner <lattner@cs.uiuc.edu>
-Subject: RE: machine instruction operands
-
-I got interrupted and forgot to explain the example. In that case:
-
- reg will be the 3rd operand of MUL and it will be of type
-MO_MInstrVirtualReg. The field MachineInstr* minstr will point to the
-instruction that computes reg.
-
- numElements will be an immediate constant, not a register.
-
- %sp will be operand 1 of ADD and it will be of type MO_MachineReg. The
-field regNum identifies the register.
-
- numElements will be operand 2 of ADD and it will be of type
-MO_VMVirtualReg. The field Value* value identifies the value.
-
- ptr will be operand 3 of ADD will also be %sp, i.e., of
- type MO_MachineReg. regNum identifies the register.
-
---Vikram
-