[mips] Support for +abs2008 attribute
Instruction abs.[ds] is not generating correct result when working
with NaNs for revisions prior mips32r6 and mips64r6.
To generate a sequence which always produce a correct result, but also
to allow user more control on how his code is compiled, attribute
+abs2008 is added, so user can choose legacy or 2008.
By default legacy mode is used on revisions prior R6. Mips32r6 and
mips64r6 use abs2008 mode by default.
Differential Revision: https://reviews.llvm.org/D35983
llvm-svn: 352370
diff --git a/llvm/lib/Target/Mips/MipsSubtarget.cpp b/llvm/lib/Target/Mips/MipsSubtarget.cpp
index 3892663..472dd72 100644
--- a/llvm/lib/Target/Mips/MipsSubtarget.cpp
+++ b/llvm/lib/Target/Mips/MipsSubtarget.cpp
@@ -72,7 +72,7 @@
unsigned StackAlignOverride)
: MipsGenSubtargetInfo(TT, CPU, FS), MipsArchVersion(MipsDefault),
IsLittle(little), IsSoftFloat(false), IsSingleFloat(false), IsFPXX(false),
- NoABICalls(false), IsFP64bit(false), UseOddSPReg(true),
+ NoABICalls(false), Abs2008(false), IsFP64bit(false), UseOddSPReg(true),
IsNaN2008bit(false), IsGP64bit(false), HasVFPU(false), HasCnMips(false),
HasMips3_32(false), HasMips3_32r2(false), HasMips4_32(false),
HasMips4_32r2(false), HasMips5_32r2(false), InMips16Mode(false),
@@ -128,11 +128,18 @@
report_fatal_error(
"indirect jumps with hazard barriers requires MIPS32R2 or later");
}
+ if (inAbs2008Mode() && hasMips32() && !hasMips32r2()) {
+ report_fatal_error("IEEE 754-2008 abs.fmt is not supported for the given "
+ "architecture.",
+ false);
+ }
+
if (hasMips32r6()) {
StringRef ISA = hasMips64r6() ? "MIPS64r6" : "MIPS32r6";
assert(isFP64bit());
assert(isNaN2008());
+ assert(inAbs2008Mode());
if (hasDSP())
report_fatal_error(ISA + " is not compatible with the DSP ASE", false);
}