Index: lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
===================================================================
--- lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
+++ lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
@@ -2266,6 +2266,26 @@
     }
   }
 
+  // If the comparison is with the results of two select instructions, check
+  // whether those conditions are inverse icmp instructions. If so, simplify to
+  // a single select on one of the conditions.
+  {
+    auto Op0Select = dyn_cast<SelectInst>(Op0);
+    auto Op1Select = dyn_cast<SelectInst>(Op1);
+    if (Op0Select && Op1Select) {
+      auto Op0Cmp = dyn_cast<CmpInst>(Op0Select->getCondition());
+      auto Op1Cmp = dyn_cast<CmpInst>(Op1Select->getCondition());
+      if (Op0Cmp && Op1Cmp &&
+          Op0Cmp->getPredicate() == Op1Cmp->getInversePredicate() &&
+          Op0Cmp->getOperand(0) == Op1Cmp->getOperand(0) &&
+          Op0Cmp->getOperand(1) == Op1Cmp->getOperand(1)) {
+            return SelectInst::Create(Op0Select->getCondition(),
+                                      Op0Select->getTrueValue(),
+                                      Op1Select->getTrueValue());
+      }
+    }
+  }
+
   return Changed ? &I : nullptr;
 }
 
Index: test/Transforms/InstCombine/logical-select.ll
===================================================================
--- test/Transforms/InstCombine/logical-select.ll
+++ test/Transforms/InstCombine/logical-select.ll
@@ -62,6 +62,22 @@
   ret i32 %t3
 }
 
+; PR32791 - https://bugs.llvm.org//show_bug.cgi?id=32791
+; Fold two selects with inverted predicates and zero operands.
+define i32 @pal(i32 %a, i32 %b, i32 %c, i32 %d) {
+; CHECK-LABEL: @pal(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 %a, %b
+; CHECK-NEXT:    [[SEL:%.*]] = select i1 [[CMP]], i32 %c, i32 %d
+; CHECK-NEXT:    ret i32 [[SEL]]
+;
+  %cmp1 = icmp slt i32 %a, %b
+  %sel1 = select i1 %cmp1, i32 %c, i32 0
+  %cmp2 = icmp sge i32 %a, %b
+  %sel2 = select i1 %cmp2, i32 %d, i32 0
+  %or = or i32 %sel1, %sel2
+  ret i32 %or
+}
+
 define i32 @par(i32 %a, i32 %b, i32 %c, i32 %d) {
 ; CHECK-LABEL: @par(
 ; CHECK-NEXT:    [[T0:%.*]] = icmp slt i32 %a, %b