[InstCombine] Fold fneg/fabs patterns with ppc_f128 (#130557)

This patch is needed by
https://github.com/llvm/llvm-project/pull/130496.

1 files changed, 16 insertions, 3 deletions

diff --git a/llvm/lib/Support/APFloat.cpp b/llvm/lib/Support/APFloat.cpp
index e058010..a7b9f25 100644
--- a/llvm/lib/Support/APFloat.cpp
+++ b/llvm/lib/Support/APFloat.cpp
@@ -125,6 +125,9 @@ struct fltSemantics {
 
   /* Whether this semantics can represent signed values */
   bool hasSignedRepr = true;
+
+  /* Whether the sign bit of this semantics is the most significant bit */
+  bool hasSignBitInMSB = true;
 };
 
 static constexpr fltSemantics semIEEEhalf = {15, -14, 11, 16};
@@ -144,9 +147,15 @@ static constexpr fltSemantics semFloat8E4M3B11FNUZ = {
     4, -10, 4, 8, fltNonfiniteBehavior::NanOnly, fltNanEncoding::NegativeZero};
 static constexpr fltSemantics semFloat8E3M4 = {3, -2, 5, 8};
 static constexpr fltSemantics semFloatTF32 = {127, -126, 11, 19};
-static constexpr fltSemantics semFloat8E8M0FNU = {
-    127,   -127, 1, 8, fltNonfiniteBehavior::NanOnly, fltNanEncoding::AllOnes,
-    false, false};
+static constexpr fltSemantics semFloat8E8M0FNU = {127,
+                                                  -127,
+                                                  1,
+                                                  8,
+                                                  fltNonfiniteBehavior::NanOnly,
+                                                  fltNanEncoding::AllOnes,
+                                                  false,
+                                                  false,
+                                                  false};
 
 static constexpr fltSemantics semFloat6E3M2FN = {
     4, -2, 3, 6, fltNonfiniteBehavior::FiniteOnly};
@@ -358,6 +367,10 @@ bool APFloatBase::isIEEELikeFP(const fltSemantics &semantics) {
   return SemanticsToEnum(semantics) <= S_IEEEquad;
 }
 
+bool APFloatBase::hasSignBitInMSB(const fltSemantics &semantics) {
+  return semantics.hasSignBitInMSB;
+}
+
 bool APFloatBase::isRepresentableAsNormalIn(const fltSemantics &Src,
                                             const fltSemantics &Dst) {
   // Exponent range must be larger.