[GlobalIsel] Combine select to integer min max more (#92570)
diff --git a/llvm/include/llvm/Target/GlobalISel/Combine.td b/llvm/include/llvm/Target/GlobalISel/Combine.td
index a1d39d9..5d4b5a2 100644
--- a/llvm/include/llvm/Target/GlobalISel/Combine.td
+++ b/llvm/include/llvm/Target/GlobalISel/Combine.td
@@ -1309,7 +1309,7 @@
def select_to_iminmax: GICombineRule<
(defs root:$root, build_fn_matchinfo:$info),
- (match (G_ICMP $tst, $tst1, $x, $y),
+ (match (G_ICMP $tst, $tst1, $a, $b),
(G_SELECT $root, $tst, $x, $y),
[{ return Helper.matchSelectIMinMax(${root}, ${info}); }]),
(apply [{ Helper.applyBuildFnMO(${root}, ${info}); }])>;
diff --git a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
index a87a26d..22eb4a3 100644
--- a/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp
@@ -6772,13 +6772,20 @@
if (CmpInst::isEquality(Pred))
return false;
- [[maybe_unused]] Register CmpLHS = Cmp->getLHSReg();
- [[maybe_unused]] Register CmpRHS = Cmp->getRHSReg();
+ Register CmpLHS = Cmp->getLHSReg();
+ Register CmpRHS = Cmp->getRHSReg();
+
+ // We can swap CmpLHS and CmpRHS for higher hitrate.
+ if (True == CmpRHS && False == CmpLHS) {
+ std::swap(CmpLHS, CmpRHS);
+ Pred = CmpInst::getSwappedPredicate(Pred);
+ }
// (icmp X, Y) ? X : Y -> integer minmax.
// see matchSelectPattern in ValueTracking.
// Legality between G_SELECT and integer minmax can differ.
- assert(True == CmpLHS && False == CmpRHS && "unexpected MIR pattern");
+ if (True != CmpLHS || False != CmpRHS)
+ return false;
switch (Pred) {
case ICmpInst::ICMP_UGT:
diff --git a/llvm/test/CodeGen/AArch64/GlobalISel/combine-select.mir b/llvm/test/CodeGen/AArch64/GlobalISel/combine-select.mir
index 8d9ad8d..353c155 100644
--- a/llvm/test/CodeGen/AArch64/GlobalISel/combine-select.mir
+++ b/llvm/test/CodeGen/AArch64/GlobalISel/combine-select.mir
@@ -911,8 +911,7 @@
; CHECK-NEXT: %f1:_(s32) = G_TRUNC [[COPY1]](s64)
; CHECK-NEXT: %t:_(<4 x s32>) = G_BUILD_VECTOR %t1(s32), %t1(s32), %t1(s32), %t1(s32)
; CHECK-NEXT: %f:_(<4 x s32>) = G_BUILD_VECTOR %f1(s32), %f1(s32), %f1(s32), %f1(s32)
- ; CHECK-NEXT: %c:_(<4 x s32>) = G_ICMP intpred(sle), %f(<4 x s32>), %t
- ; CHECK-NEXT: %sel:_(<4 x s32>) = exact G_SELECT %c(<4 x s32>), %t, %f
+ ; CHECK-NEXT: %sel:_(<4 x s32>) = G_SMAX %t, %f
; CHECK-NEXT: $q0 = COPY %sel(<4 x s32>)
%0:_(s64) = COPY $x0
%1:_(s64) = COPY $x1
