Skip to content

Commit

Permalink
Fix the encoding of the armv7m (MClass) for MSR APSR writes which was…
Browse files Browse the repository at this point in the history 
… missing

the 0b10 mask encoding bits.  Make MSR APSR writes without a _<bits> qualifier
an alias for MSR APSR_nzcvq even though ARM as deprecated it use.  Also add
support for suffixes (_nzcvq, _g, _nzcvqg) for APSR versions.  Some FIXMEs in
the code for better error checking when versions shouldn't be used.
rdar://11457025


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157019 91177308-0d34-0410-b5e6-96231b3b80d8
  • Loading branch information
@enderby
enderby committed May 17, 2012
1 parent bb8cef5 commit 0fd4f3c
Show file tree
Hide file tree
Showing 4 changed files with 82 additions and 15 deletions.
4 changes: 2 additions & 2 deletions lib/Target/ARM/ARMInstrThumb2.td
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3683,13 +3683,13 @@ def t2MSR_AR : T2I<(outs), (ins msr_mask:$mask, rGPR:$Rn),
def t2MSR_M : T2I<(outs), (ins msr_mask:$SYSm, rGPR:$Rn),
NoItinerary, "msr", "\t$SYSm, $Rn", []>,
Requires<[IsThumb,IsMClass]> {
bits<8> SYSm;
bits<12> SYSm;
bits<4> Rn;
let Inst{31-21} = 0b11110011100;
let Inst{20} = 0b0;
let Inst{19-16} = Rn;
let Inst{15-12} = 0b1000;
let Inst{7-0} = SYSm;
let Inst{11-0} = SYSm;
}


Expand Down
33 changes: 29 additions & 4 deletions lib/Target/ARM/AsmParser/ARMAsmParser.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3324,10 +3324,35 @@ parseMSRMaskOperand(SmallVectorImpl<MCParsedAsmOperand*> &Operands) {
// See ARMv6-M 10.1.1
std::string Name = Mask.lower();
unsigned FlagsVal = StringSwitch<unsigned>(Name)
.Case("apsr", 0)
.Case("iapsr", 1)
.Case("eapsr", 2)
.Case("xpsr", 3)
// Note: in the documentation:
// ARM deprecates using MSR APSR without a _<bits> qualifier as an alias
// for MSR APSR_nzcvq.
// but we do make it an alias here. This is so to get the "mask encoding"
// bits correct on MSR APSR writes.
//
// FIXME: Note the 0xc00 "mask encoding" bits version of the registers
// should really only be allowed when writing a special register. Note
// they get dropped in the MRS instruction reading a special register as
// the SYSm field is only 8 bits.
//
// FIXME: the _g and _nzcvqg versions are only allowed if the processor
// includes the DSP extension but that is not checked.
.Case("apsr", 0x800)
.Case("apsr_nzcvq", 0x800)
.Case("apsr_g", 0x400)
.Case("apsr_nzcvqg", 0xc00)
.Case("iapsr", 0x801)
.Case("iapsr_nzcvq", 0x801)
.Case("iapsr_g", 0x401)
.Case("iapsr_nzcvqg", 0xc01)
.Case("eapsr", 0x802)
.Case("eapsr_nzcvq", 0x802)
.Case("eapsr_g", 0x402)
.Case("eapsr_nzcvqg", 0xc02)
.Case("xpsr", 0x803)
.Case("xpsr_nzcvq", 0x803)
.Case("xpsr_g", 0x403)
.Case("xpsr_nzcvqg", 0xc03)
.Case("ipsr", 5)
.Case("epsr", 6)
.Case("iepsr", 7)
Expand Down
28 changes: 23 additions & 5 deletions lib/Target/ARM/InstPrinter/ARMInstPrinter.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -647,12 +647,30 @@ void ARMInstPrinter::printMSRMaskOperand(const MCInst *MI, unsigned OpNum,
unsigned Mask = Op.getImm() & 0xf;

if (getAvailableFeatures() & ARM::FeatureMClass) {
switch (Op.getImm()) {
unsigned SYSm = Op.getImm();
unsigned Opcode = MI->getOpcode();
// For reads of the special registers ignore the "mask encoding" bits
// which are only for writes.
if (Opcode == ARM::t2MRS_M)
SYSm &= 0xff;
switch (SYSm) {
default: llvm_unreachable("Unexpected mask value!");
case 0: O << "apsr"; return;
case 1: O << "iapsr"; return;
case 2: O << "eapsr"; return;
case 3: O << "xpsr"; return;
case 0:
case 0x800: O << "apsr"; return; // with _nzcvq bits is an alias for aspr
case 0x400: O << "apsr_g"; return;
case 0xc00: O << "apsr_nzcvqg"; return;
case 1:
case 0x801: O << "iapsr"; return; // with _nzcvq bits is an alias for iapsr
case 0x401: O << "iapsr_g"; return;
case 0xc01: O << "iapsr_nzcvqg"; return;
case 2:
case 0x802: O << "eapsr"; return; // with _nzcvq bits is an alias for eapsr
case 0x402: O << "eapsr_g"; return;
case 0xc02: O << "eapsr_nzcvqg"; return;
case 3:
case 0x803: O << "xpsr"; return; // with _nzcvq bits is an alias for xpsr
case 0x403: O << "xpsr_g"; return;
case 0xc03: O << "xpsr_nzcvqg"; return;
case 5: O << "ipsr"; return;
case 6: O << "epsr"; return;
case 7: O << "iepsr"; return;
Expand Down
32 changes: 28 additions & 4 deletions test/MC/ARM/thumb2-mclass.s
View file
Original file line number Diff line number Diff line change
Expand Up @@ -44,9 +44,21 @@
@------------------------------------------------------------------------------

msr apsr, r0
msr apsr_nzcvq, r0
msr apsr_g, r0
msr apsr_nzcvqg, r0
msr iapsr, r0
msr iapsr_nzcvq, r0
msr iapsr_g, r0
msr iapsr_nzcvqg, r0
msr eapsr, r0
msr eapsr_nzcvq, r0
msr eapsr_g, r0
msr eapsr_nzcvqg, r0
msr xpsr, r0
msr xpsr_nzcvq, r0
msr xpsr_g, r0
msr xpsr_nzcvqg, r0
msr ipsr, r0
msr epsr, r0
msr iepsr, r0
Expand All @@ -58,10 +70,22 @@
msr faultmask, r0
msr control, r0

@ CHECK: msr apsr, r0 @ encoding: [0x80,0xf3,0x00,0x80]
@ CHECK: msr iapsr, r0 @ encoding: [0x80,0xf3,0x01,0x80]
@ CHECK: msr eapsr, r0 @ encoding: [0x80,0xf3,0x02,0x80]
@ CHECK: msr xpsr, r0 @ encoding: [0x80,0xf3,0x03,0x80]
@ CHECK: msr apsr, r0 @ encoding: [0x80,0xf3,0x00,0x88]
@ CHECK: msr apsr, r0 @ encoding: [0x80,0xf3,0x00,0x88]
@ CHECK: msr apsr_g, r0 @ encoding: [0x80,0xf3,0x00,0x84]
@ CHECK: msr apsr_nzcvqg, r0 @ encoding: [0x80,0xf3,0x00,0x8c]
@ CHECK: msr iapsr, r0 @ encoding: [0x80,0xf3,0x01,0x88]
@ CHECK: msr iapsr, r0 @ encoding: [0x80,0xf3,0x01,0x88]
@ CHECK: msr iapsr_g, r0 @ encoding: [0x80,0xf3,0x01,0x84]
@ CHECK: msr iapsr_nzcvqg, r0 @ encoding: [0x80,0xf3,0x01,0x8c]
@ CHECK: msr eapsr, r0 @ encoding: [0x80,0xf3,0x02,0x88]
@ CHECK: msr eapsr, r0 @ encoding: [0x80,0xf3,0x02,0x88]
@ CHECK: msr eapsr_g, r0 @ encoding: [0x80,0xf3,0x02,0x84]
@ CHECK: msr eapsr_nzcvqg, r0 @ encoding: [0x80,0xf3,0x02,0x8c]
@ CHECK: msr xpsr, r0 @ encoding: [0x80,0xf3,0x03,0x88]
@ CHECK: msr xpsr, r0 @ encoding: [0x80,0xf3,0x03,0x88]
@ CHECK: msr xpsr_g, r0 @ encoding: [0x80,0xf3,0x03,0x84]
@ CHECK: msr xpsr_nzcvqg, r0 @ encoding: [0x80,0xf3,0x03,0x8c]
@ CHECK: msr ipsr, r0 @ encoding: [0x80,0xf3,0x05,0x80]
@ CHECK: msr epsr, r0 @ encoding: [0x80,0xf3,0x06,0x80]
@ CHECK: msr iepsr, r0 @ encoding: [0x80,0xf3,0x07,0x80]
Expand Down

0 comments on commit 0fd4f3c

Please sign in to comment.