Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3416,8 +3416,8 @@
     }
 
     Known = computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1);
-    if (Known.isUnknown()) break; // Early-out
     Known2 = computeKnownBits(Op.getOperand(1), DemandedElts, Depth + 1);
+    if (Known.isUnknown() && Known2.isUnknown()) break; // Early-out
     if (IsMax)
       Known = KnownBits::smax(Known, Known2);
     else
Index: llvm/test/CodeGen/X86/avx512-trunc.ll
===================================================================
--- llvm/test/CodeGen/X86/avx512-trunc.ll
+++ llvm/test/CodeGen/X86/avx512-trunc.ll
@@ -1007,21 +1007,14 @@
 define void @negative_test1_smax_usat_trunc_wb_256_mem(<16 x i16> %i, <16 x i8>* %res) {
 ; KNL-LABEL: negative_test1_smax_usat_trunc_wb_256_mem:
 ; KNL:       ## %bb.0:
-; KNL-NEXT:    vpxor %xmm1, %xmm1, %xmm1
-; KNL-NEXT:    vpmaxsw %ymm1, %ymm0, %ymm0
-; KNL-NEXT:    vpcmpeqd %ymm1, %ymm1, %ymm1
-; KNL-NEXT:    vpminsw %ymm1, %ymm0, %ymm0
-; KNL-NEXT:    vpmovzxwd {{.*#+}} zmm0 = ymm0[0],zero,ymm0[1],zero,ymm0[2],zero,ymm0[3],zero,ymm0[4],zero,ymm0[5],zero,ymm0[6],zero,ymm0[7],zero,ymm0[8],zero,ymm0[9],zero,ymm0[10],zero,ymm0[11],zero,ymm0[12],zero,ymm0[13],zero,ymm0[14],zero,ymm0[15],zero
+; KNL-NEXT:    vpbroadcastd {{.*#+}} zmm0 = [255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255]
 ; KNL-NEXT:    vpmovdb %zmm0, (%rdi)
 ; KNL-NEXT:    vzeroupper
 ; KNL-NEXT:    retq
 ;
 ; SKX-LABEL: negative_test1_smax_usat_trunc_wb_256_mem:
 ; SKX:       ## %bb.0:
-; SKX-NEXT:    vpxor %xmm1, %xmm1, %xmm1
-; SKX-NEXT:    vpmaxsw %ymm1, %ymm0, %ymm0
-; SKX-NEXT:    vpcmpeqd %ymm1, %ymm1, %ymm1
-; SKX-NEXT:    vpminsw %ymm1, %ymm0, %ymm0
+; SKX-NEXT:    vpcmpeqd %ymm0, %ymm0, %ymm0
 ; SKX-NEXT:    vpmovwb %ymm0, (%rdi)
 ; SKX-NEXT:    vzeroupper
 ; SKX-NEXT:    retq
Index: llvm/test/CodeGen/X86/known-bits-vector.ll
===================================================================
--- llvm/test/CodeGen/X86/known-bits-vector.ll
+++ llvm/test/CodeGen/X86/known-bits-vector.ll
@@ -435,11 +435,7 @@
 ; X32-NEXT:    vpminsd {{\.LCPI.*}}, %xmm0, %xmm0
 ; X32-NEXT:    vpmaxsd {{\.LCPI.*}}, %xmm0, %xmm0
 ; X32-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[0,0,3,3]
-; X32-NEXT:    vpblendw {{.*#+}} xmm1 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; X32-NEXT:    vpsrld $16, %xmm0, %xmm0
-; X32-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; X32-NEXT:    vsubps {{\.LCPI.*}}, %xmm0, %xmm0
-; X32-NEXT:    vaddps %xmm0, %xmm1, %xmm0
+; X32-NEXT:    vcvtdq2ps %xmm0, %xmm0
 ; X32-NEXT:    retl
 ;
 ; X64-LABEL: knownbits_smax_smin_shuffle_uitofp:
@@ -447,11 +443,7 @@
 ; X64-NEXT:    vpminsd {{.*}}(%rip), %xmm0, %xmm0
 ; X64-NEXT:    vpmaxsd {{.*}}(%rip), %xmm0, %xmm0
 ; X64-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[0,0,3,3]
-; X64-NEXT:    vpblendw {{.*#+}} xmm1 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; X64-NEXT:    vpsrld $16, %xmm0, %xmm0
-; X64-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; X64-NEXT:    vsubps {{.*}}(%rip), %xmm0, %xmm0
-; X64-NEXT:    vaddps %xmm0, %xmm1, %xmm0
+; X64-NEXT:    vcvtdq2ps %xmm0, %xmm0
 ; X64-NEXT:    retq
   %1 = call <4 x i32> @llvm.x86.sse41.pminsd(<4 x i32> %a0, <4 x i32> <i32 0, i32 -65535, i32 -65535, i32 0>)
   %2 = call <4 x i32> @llvm.x86.sse41.pmaxsd(<4 x i32> %1, <4 x i32> <i32 65535, i32 -1, i32 -1, i32 131071>)