[mips] Add error message when trying to use $at in '.set noat' mode.

Summary:
Patch by David Chisnall
His work was sponsored by: DARPA, AFRL

Differential Revision: http://llvm-reviews.chandlerc.com/D3158

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204621 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Daniel Sanders 2014-03-24 16:48:01 +00:00
parent 2685aa8713
commit 8ce101ed10
2 changed files with 33 additions and 1 deletions

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@ -1174,7 +1174,12 @@ bool MipsAssemblerOptions::setATReg(unsigned Reg) {
return true;
}
int MipsAsmParser::getATReg() { return Options.getATRegNum(); }
int MipsAsmParser::getATReg() {
int AT = Options.getATRegNum();
if (AT == 0)
TokError("Pseudo instruction requires $at, which is not available");
return AT;
}
unsigned MipsAsmParser::getReg(int RC, int RegNo) {
return *(getContext().getRegisterInfo()->getRegClass(RC).begin() + RegNo);

27
test/MC/Mips/mips-noat.s Normal file
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@ -0,0 +1,27 @@
# RUN: not llvm-mc %s -triple=mips-unknown-linux 2>%t0 | FileCheck %s
# RUN: FileCheck -check-prefix=ERROR %s < %t0
# We start with $at enabled
# CHECK-LABEL: test1:
# CHECK: lui $1, 1
# CHECK: addu $1, $1, $2
# CHECK: lw $2, 0($1)
test1:
lw $2, 65536($2)
# Check that using $at when .set noat is in effect is an error.
# FIXME: It would be better if the error pointed at the mnemonic instead of the newline
# ERROR: mips-noat.s:[[@LINE+5]]:1: error: Pseudo instruction requires $at, which is not available
# ERROR-NOT: error
test2:
.set noat
lw $2, 65536($2)
# Can we switch it back on successfully?
# CHECK-LABEL: test3:
# CHECK: lui $1, 1
# CHECK: addu $1, $1, $2
# CHECK: lw $2, 0($1)
test3:
.set at
lw $2, 65536($2)