[llvm-commits] [llvm] r112387 - in /llvm/trunk/lib/Target/X86/AsmPrinter: CMakeLists.txt X86ATTInstPrinter.cpp X86InstComments.cpp X86InstComments.h X86IntelInstPrinter.cpp
Chris Lattner
sabre at nondot.org
Sat Aug 28 13:42:31 PDT 2010
Author: lattner
Date: Sat Aug 28 15:42:31 2010
New Revision: 112387
URL: http://llvm.org/viewvc/llvm-project?rev=112387&view=rev
Log:
I have manually decoded the imm field of an insertps one too many
times. This patch causes llc and llvm-mc (which both default to
verbose-asm) to print out comments after a few common shuffle
instructions which indicates the shuffle mask, e.g.:
insertps $113, %xmm3, %xmm0 ## xmm0 = zero,xmm0[1,2],xmm3[1]
unpcklps %xmm1, %xmm0 ## xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
pshufd $1, %xmm1, %xmm1 ## xmm1 = xmm1[1,0,0,0]
This is carefully factored to keep the information extraction (of the
shuffle mask) separate from the printing logic. I plan to move the
extraction part out somewhere else at some point for other parts of
the x86 backend that want to introspect on the behavior of shuffles.
Added:
llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.cpp
llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.h
Modified:
llvm/trunk/lib/Target/X86/AsmPrinter/CMakeLists.txt
llvm/trunk/lib/Target/X86/AsmPrinter/X86ATTInstPrinter.cpp
llvm/trunk/lib/Target/X86/AsmPrinter/X86IntelInstPrinter.cpp
Modified: llvm/trunk/lib/Target/X86/AsmPrinter/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/AsmPrinter/CMakeLists.txt?rev=112387&r1=112386&r2=112387&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/AsmPrinter/CMakeLists.txt (original)
+++ llvm/trunk/lib/Target/X86/AsmPrinter/CMakeLists.txt Sat Aug 28 15:42:31 2010
@@ -3,5 +3,6 @@
add_llvm_library(LLVMX86AsmPrinter
X86ATTInstPrinter.cpp
X86IntelInstPrinter.cpp
+ X86InstComments.cpp
)
add_dependencies(LLVMX86AsmPrinter X86CodeGenTable_gen)
Modified: llvm/trunk/lib/Target/X86/AsmPrinter/X86ATTInstPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/AsmPrinter/X86ATTInstPrinter.cpp?rev=112387&r1=112386&r2=112387&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/AsmPrinter/X86ATTInstPrinter.cpp (original)
+++ llvm/trunk/lib/Target/X86/AsmPrinter/X86ATTInstPrinter.cpp Sat Aug 28 15:42:31 2010
@@ -14,6 +14,7 @@
#define DEBUG_TYPE "asm-printer"
#include "X86ATTInstPrinter.h"
+#include "X86InstComments.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
@@ -31,6 +32,10 @@
void X86ATTInstPrinter::printInst(const MCInst *MI, raw_ostream &OS) {
printInstruction(MI, OS);
+
+ // If verbose assembly is enabled, we can print some informative comments.
+ if (CommentStream)
+ EmitAnyX86InstComments(MI, *CommentStream, getRegisterName);
}
StringRef X86ATTInstPrinter::getOpcodeName(unsigned Opcode) const {
return getInstructionName(Opcode);
Added: llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.cpp?rev=112387&view=auto
==============================================================================
--- llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.cpp (added)
+++ llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.cpp Sat Aug 28 15:42:31 2010
@@ -0,0 +1,184 @@
+//===-- X86InstComments.cpp - Generate verbose-asm comments for instrs ----===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines functionality used to emit comments about X86 instructions to
+// an output stream for -fverbose-asm.
+//
+//===----------------------------------------------------------------------===//
+
+#include "X86InstComments.h"
+#include "X86GenInstrNames.inc"
+#include "llvm/MC/MCInst.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Vector Mask Decoding
+//===----------------------------------------------------------------------===//
+
+enum {
+ SM_SentinelZero = ~0U
+};
+
+static void DecodeINSERTPSMask(unsigned Imm,
+ SmallVectorImpl<unsigned> &ShuffleMask) {
+ // Defaults the copying the dest value.
+ ShuffleMask.push_back(0);
+ ShuffleMask.push_back(1);
+ ShuffleMask.push_back(2);
+ ShuffleMask.push_back(3);
+
+ // Decode the immediate.
+ unsigned ZMask = Imm & 15;
+ unsigned CountD = (Imm >> 4) & 3;
+ unsigned CountS = (Imm >> 6) & 3;
+
+ // CountS selects which input element to use.
+ unsigned InVal = 4+CountS;
+ // CountD specifies which element of destination to update.
+ ShuffleMask[CountD] = InVal;
+ // ZMask zaps values, potentially overriding the CountD elt.
+ if (ZMask & 1) ShuffleMask[0] = SM_SentinelZero;
+ if (ZMask & 2) ShuffleMask[1] = SM_SentinelZero;
+ if (ZMask & 4) ShuffleMask[2] = SM_SentinelZero;
+ if (ZMask & 8) ShuffleMask[3] = SM_SentinelZero;
+}
+
+static void DecodeSHUFPSMask(unsigned NElts, unsigned Imm,
+ SmallVectorImpl<unsigned> &ShuffleMask) {
+ // Part that reads from dest.
+ for (unsigned i = 0; i != NElts/2; ++i) {
+ ShuffleMask.push_back(Imm % NElts);
+ Imm /= NElts;
+ }
+ // Part that reads from src.
+ for (unsigned i = 0; i != NElts/2; ++i) {
+ ShuffleMask.push_back(Imm % NElts + NElts);
+ Imm /= NElts;
+ }
+}
+
+static void DecodePSHUFMask(unsigned NElts, unsigned Imm,
+ SmallVectorImpl<unsigned> &ShuffleMask) {
+ for (unsigned i = 0; i != NElts; ++i) {
+ ShuffleMask.push_back(Imm % NElts);
+ Imm /= NElts;
+ }
+}
+
+/// DecodeUNPCKLPMask - This decodes the shuffle masks for unpcklps/unpcklpd
+/// etc. NElts indicates the number of elements in the vector allowing it to
+/// handle different datatypes and vector widths.
+static void DecodeUNPCKLPMask(unsigned NElts,
+ SmallVectorImpl<unsigned> &ShuffleMask) {
+ for (unsigned i = 0; i != NElts/2; ++i) {
+ ShuffleMask.push_back(i); // Reads from dest
+ ShuffleMask.push_back(i+NElts); // Reads from src
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// Top Level Entrypoint
+//===----------------------------------------------------------------------===//
+
+
+/// EmitAnyX86InstComments - This function decodes x86 instructions and prints
+/// newline terminated strings to the specified string if desired. This
+/// information is shown in disassembly dumps when verbose assembly is enabled.
+void llvm::EmitAnyX86InstComments(const MCInst *MI, raw_ostream &OS,
+ const char *(*getRegName)(unsigned)) {
+ // If this is a shuffle operation, the switch should fill in this state.
+ SmallVector<unsigned, 8> ShuffleMask;
+ const char *DestName = 0, *Src1Name = 0, *Src2Name = 0;
+
+ switch (MI->getOpcode()) {
+ case X86::INSERTPSrr:
+ Src1Name = getRegName(MI->getOperand(1).getReg());
+ Src2Name = getRegName(MI->getOperand(2).getReg());
+ DecodeINSERTPSMask(MI->getOperand(3).getImm(), ShuffleMask);
+ break;
+ case X86::PSHUFDri:
+ Src1Name = getRegName(MI->getOperand(1).getReg());
+ // FALL THROUGH.
+ case X86::PSHUFDmi:
+ DestName = getRegName(MI->getOperand(0).getReg());
+ DecodePSHUFMask(4, MI->getOperand(MI->getNumOperands()-1).getImm(),
+ ShuffleMask);
+ break;
+
+ case X86::SHUFPDrri:
+ DecodeSHUFPSMask(2, MI->getOperand(3).getImm(), ShuffleMask);
+ Src1Name = getRegName(MI->getOperand(0).getReg());
+ Src2Name = getRegName(MI->getOperand(2).getReg());
+ break;
+ case X86::SHUFPSrri:
+ DecodeSHUFPSMask(4, MI->getOperand(3).getImm(), ShuffleMask);
+ Src1Name = getRegName(MI->getOperand(0).getReg());
+ Src2Name = getRegName(MI->getOperand(2).getReg());
+ break;
+ case X86::UNPCKLPSrr:
+ Src2Name = getRegName(MI->getOperand(2).getReg());
+ // FALL THROUGH.
+ case X86::UNPCKLPSrm:
+ DecodeUNPCKLPMask(4, ShuffleMask);
+ Src1Name = getRegName(MI->getOperand(0).getReg());
+ break;
+ }
+
+
+ // If this was a shuffle operation, print the shuffle mask.
+ if (!ShuffleMask.empty()) {
+ if (DestName == 0) DestName = Src1Name;
+ OS << (DestName ? DestName : "mem") << " = ";
+
+ // If the two sources are the same, canonicalize the input elements to be
+ // from the first src so that we get larger element spans.
+ if (Src1Name == Src2Name) {
+ for (unsigned i = 0, e = ShuffleMask.size(); i != e; ++i) {
+ if ((int)ShuffleMask[i] >= 0 && // Not sentinel.
+ ShuffleMask[i] >= e) // From second mask.
+ ShuffleMask[i] -= e;
+ }
+ }
+
+ // The shuffle mask specifies which elements of the src1/src2 fill in the
+ // destination, with a few sentinel values. Loop through and print them
+ // out.
+ for (unsigned i = 0, e = ShuffleMask.size(); i != e; ++i) {
+ if (i != 0)
+ OS << ',';
+ if (ShuffleMask[i] == SM_SentinelZero) {
+ OS << "zero";
+ continue;
+ }
+
+ // Otherwise, it must come from src1 or src2. Print the span of elements
+ // that comes from this src.
+ bool isSrc1 = ShuffleMask[i] < ShuffleMask.size();
+ const char *SrcName = isSrc1 ? Src1Name : Src2Name;
+ OS << (SrcName ? SrcName : "mem") << '[';
+ bool IsFirst = true;
+ while (i != e &&
+ (int)ShuffleMask[i] >= 0 &&
+ (ShuffleMask[i] < ShuffleMask.size()) == isSrc1) {
+ if (!IsFirst)
+ OS << ',';
+ else
+ IsFirst = false;
+ OS << ShuffleMask[i] % ShuffleMask.size();
+ ++i;
+ }
+ OS << ']';
+ --i; // For loop increments element #.
+ }
+ //MI->print(OS, 0);
+ OS << "\n";
+ }
+
+}
Added: llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.h?rev=112387&view=auto
==============================================================================
--- llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.h (added)
+++ llvm/trunk/lib/Target/X86/AsmPrinter/X86InstComments.h Sat Aug 28 15:42:31 2010
@@ -0,0 +1,25 @@
+//===-- X86InstComments.h - Generate verbose-asm comments for instrs ------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This defines functionality used to emit comments about X86 instructions to
+// an output stream for -fverbose-asm.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef X86_INST_COMMENTS_H
+#define X86_INST_COMMENTS_H
+
+namespace llvm {
+ class MCInst;
+ class raw_ostream;
+ void EmitAnyX86InstComments(const MCInst *MI, raw_ostream &OS,
+ const char *(*getRegName)(unsigned));
+}
+
+#endif
Modified: llvm/trunk/lib/Target/X86/AsmPrinter/X86IntelInstPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/AsmPrinter/X86IntelInstPrinter.cpp?rev=112387&r1=112386&r2=112387&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/AsmPrinter/X86IntelInstPrinter.cpp (original)
+++ llvm/trunk/lib/Target/X86/AsmPrinter/X86IntelInstPrinter.cpp Sat Aug 28 15:42:31 2010
@@ -14,6 +14,7 @@
#define DEBUG_TYPE "asm-printer"
#include "X86IntelInstPrinter.h"
+#include "X86InstComments.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCExpr.h"
@@ -30,6 +31,10 @@
void X86IntelInstPrinter::printInst(const MCInst *MI, raw_ostream &OS) {
printInstruction(MI, OS);
+
+ // If verbose assembly is enabled, we can print some informative comments.
+ if (CommentStream)
+ EmitAnyX86InstComments(MI, *CommentStream, getRegisterName);
}
StringRef X86IntelInstPrinter::getOpcodeName(unsigned Opcode) const {
return getInstructionName(Opcode);
More information about the llvm-commits
mailing list