Index: llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
===================================================================
--- llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -1736,6 +1736,7 @@
 /// And X - Y overflows ? 0 : X - Y -> usub_sat X, Y
 /// Along with a number of patterns similar to:
 /// X + Y overflows ? (X < 0 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
+/// X - Y overflows ? (X > 0 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
 static Instruction *
 foldOverflowingAddSubSelect(SelectInst &SI, InstCombiner::BuilderTy &Builder) {
   Value *CondVal = SI.getCondition();
@@ -1750,7 +1751,7 @@
   Value *X = II->getLHS();
   Value *Y = II->getRHS();
 
-  auto IsSignedSaturateLimit = [&](Value *Limit) {
+  auto IsSignedSaturateLimit = [&](Value *Limit, bool IsAdd) {
     Type *Ty = Limit->getType();
 
     ICmpInst::Predicate Pred;
@@ -1773,20 +1774,43 @@
     if (Op != X && Op != Y)
       return false;
 
-    // X + Y overflows ? (X <s 0 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
-    // X + Y overflows ? (X <s 1 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
-    // X + Y overflows ? (Y <s 0 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
-    // X + Y overflows ? (Y <s 1 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
-    if (Pred == ICmpInst::ICMP_SLT && IsZeroOrOne(*C) &&
-        IsMinMax(TrueVal, FalseVal))
-      return true;
-    // X + Y overflows ? (X >s 0 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
-    // X + Y overflows ? (X >s -1 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
-    // X + Y overflows ? (Y >s 0 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
-    // X + Y overflows ? (Y >s -1 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
-    if (Pred == ICmpInst::ICMP_SGT && IsZeroOrOne(*C + 1) &&
-        IsMinMax(FalseVal, TrueVal))
-      return true;
+    if (IsAdd) {
+      // X + Y overflows ? (X <s 0 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
+      // X + Y overflows ? (X <s 1 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
+      // X + Y overflows ? (Y <s 0 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
+      // X + Y overflows ? (Y <s 1 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
+      if (Pred == ICmpInst::ICMP_SLT && IsZeroOrOne(*C) &&
+          IsMinMax(TrueVal, FalseVal))
+        return true;
+      // X + Y overflows ? (X >s 0 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
+      // X + Y overflows ? (X >s -1 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
+      // X + Y overflows ? (Y >s 0 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
+      // X + Y overflows ? (Y >s -1 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
+      if (Pred == ICmpInst::ICMP_SGT && IsZeroOrOne(*C + 1) &&
+          IsMinMax(FalseVal, TrueVal))
+        return true;
+    } else {
+      // X - Y overflows ? (X <s 0 ? INTMIN : INTMAX) : X - Y --> ssub_sat X, Y
+      // X - Y overflows ? (X <s -1 ? INTMIN : INTMAX) : X - Y --> ssub_sat X, Y
+      if (Op == X && Pred == ICmpInst::ICMP_SLT && IsZeroOrOne(*C + 1) &&
+          IsMinMax(TrueVal, FalseVal))
+        return true;
+      // X - Y overflows ? (X >s -1 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
+      // X - Y overflows ? (X >s -2 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
+      if (Op == X && Pred == ICmpInst::ICMP_SGT && IsZeroOrOne(*C + 2) &&
+          IsMinMax(FalseVal, TrueVal))
+        return true;
+      // X - Y overflows ? (Y <s 0 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
+      // X - Y overflows ? (Y <s 1 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
+      if (Op == Y && Pred == ICmpInst::ICMP_SLT && IsZeroOrOne(*C) &&
+          IsMinMax(FalseVal, TrueVal))
+        return true;
+      // X - Y overflows ? (Y >s 0 ? INTMIN : INTMAX) : X - Y --> ssub_sat X, Y
+      // X - Y overflows ? (Y >s -1 ? INTMIN : INTMAX) : X - Y --> ssub_sat X, Y
+      if (Op == Y && Pred == ICmpInst::ICMP_SGT && IsZeroOrOne(*C + 1) &&
+          IsMinMax(TrueVal, FalseVal))
+        return true;
+    }
 
     return false;
   };
@@ -1801,7 +1825,7 @@
     // X - Y overflows ? 0 : X - Y -> usub_sat X, Y
     NewIntrinsicID = Intrinsic::usub_sat;
   else if (II->getIntrinsicID() == Intrinsic::sadd_with_overflow &&
-           IsSignedSaturateLimit(TrueVal))
+           IsSignedSaturateLimit(TrueVal, /*IsAdd=*/true))
     // X + Y overflows ? (X <s 0 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
     // X + Y overflows ? (X <s 1 ? INTMIN : INTMAX) : X + Y --> sadd_sat X, Y
     // X + Y overflows ? (X >s 0 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
@@ -1811,6 +1835,17 @@
     // X + Y overflows ? (Y >s 0 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
     // X + Y overflows ? (Y >s -1 ? INTMAX : INTMIN) : X + Y --> sadd_sat X, Y
     NewIntrinsicID = Intrinsic::sadd_sat;
+  else if (II->getIntrinsicID() == Intrinsic::ssub_with_overflow &&
+           IsSignedSaturateLimit(TrueVal, /*IsAdd=*/false))
+    // X - Y overflows ? (X <s 0 ? INTMIN : INTMAX) : X - Y --> ssub_sat X, Y
+    // X - Y overflows ? (X <s -1 ? INTMIN : INTMAX) : X - Y --> ssub_sat X, Y
+    // X - Y overflows ? (X >s -1 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
+    // X - Y overflows ? (X >s -2 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
+    // X - Y overflows ? (Y <s 0 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
+    // X - Y overflows ? (Y <s 1 ? INTMAX : INTMIN) : X - Y --> ssub_sat X, Y
+    // X - Y overflows ? (Y >s 0 ? INTMIN : INTMAX) : X - Y --> ssub_sat X, Y
+    // X - Y overflows ? (Y >s -1 ? INTMIN : INTMAX) : X - Y --> ssub_sat X, Y
+    NewIntrinsicID = Intrinsic::ssub_sat;
   else
     return nullptr;
 
Index: llvm/test/Transforms/InstCombine/overflow_to_sat.ll
===================================================================
--- llvm/test/Transforms/InstCombine/overflow_to_sat.ll
+++ llvm/test/Transforms/InstCombine/overflow_to_sat.ll
@@ -315,12 +315,7 @@
 
 define i8 @ssub_x_lt_max(i8 %x, i8 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_x_lt_max(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i8, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i8, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp slt i8 [[X]], 0
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i8 -128, i8 127
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i8 [[S]], i8 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %ao = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 %x, i8 %y)
@@ -391,12 +386,7 @@
 
 define i8 @ssub_x_lt2_max(i8 %x, i8 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_x_lt2_max(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i8, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i8, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp slt i8 [[X]], -1
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i8 -128, i8 127
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i8 [[S]], i8 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %ao = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 %x, i8 %y)
@@ -448,12 +438,7 @@
 
 define i8 @ssub_x_ge_min(i8 %x, i8 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_x_ge_min(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i8, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i8, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp sgt i8 [[X]], -1
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i8 127, i8 -128
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i8 [[S]], i8 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %ao = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 %x, i8 %y)
@@ -486,12 +471,7 @@
 
 define i8 @ssub_x_gt2_min(i8 %x, i8 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_x_gt2_min(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i8, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i8, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp sgt i8 [[X]], -2
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i8 127, i8 -128
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i8 [[S]], i8 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %ao = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 %x, i8 %y)
@@ -525,12 +505,7 @@
 
 define i8 @ssub_y_lt_min(i8 %x, i8 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_y_lt_min(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i8, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i8, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp slt i8 [[Y]], 0
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i8 127, i8 -128
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i8 [[S]], i8 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %ao = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 %x, i8 %y)
@@ -563,12 +538,7 @@
 
 define i8 @ssub_y_le_min(i8 %x, i8 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_y_le_min(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i8, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i8, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp slt i8 [[Y]], 1
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i8 127, i8 -128
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i8 [[S]], i8 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %ao = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 %x, i8 %y)
@@ -620,12 +590,7 @@
 
 define i8 @ssub_y_gt_max(i8 %x, i8 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_y_gt_max(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i8, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i8, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp sgt i8 [[Y]], 0
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i8 -128, i8 127
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i8 [[S]], i8 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %ao = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 %x, i8 %y)
@@ -658,12 +623,7 @@
 
 define i8 @ssub_y_ge_max(i8 %x, i8 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_y_ge_max(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i8, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i8, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp sgt i8 [[Y]], -1
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i8 -128, i8 127
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i8 [[S]], i8 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i8 @llvm.ssub.sat.i8(i8 [[X:%.*]], i8 [[Y:%.*]])
 ; CHECK-NEXT:    ret i8 [[R]]
 ;
   %ao = tail call { i8, i1 } @llvm.ssub.with.overflow.i8(i8 %x, i8 %y)
@@ -692,12 +652,7 @@
 
 define i32 @ssub_i32(i32 %x, i32 %y) {
 ; CHECK-LABEL: define {{[^@]+}}@ssub_i32(
-; CHECK-NEXT:    [[AO:%.*]] = tail call { i32, i1 } @llvm.ssub.with.overflow.i32(i32 [[X:%.*]], i32 [[Y:%.*]])
-; CHECK-NEXT:    [[O:%.*]] = extractvalue { i32, i1 } [[AO]], 1
-; CHECK-NEXT:    [[A:%.*]] = extractvalue { i32, i1 } [[AO]], 0
-; CHECK-NEXT:    [[C:%.*]] = icmp slt i32 [[X]], 0
-; CHECK-NEXT:    [[S:%.*]] = select i1 [[C]], i32 -2147483648, i32 2147483647
-; CHECK-NEXT:    [[R:%.*]] = select i1 [[O]], i32 [[S]], i32 [[A]]
+; CHECK-NEXT:    [[R:%.*]] = call i32 @llvm.ssub.sat.i32(i32 [[X:%.*]], i32 [[Y:%.*]])
 ; CHECK-NEXT:    ret i32 [[R]]
 ;
   %ao = tail call { i32, i1 } @llvm.ssub.with.overflow.i32(i32 %x, i32 %y)