[NVPTX][AutoUpgrade] Use integer min/max intrinsics instead of icmp, select

[AlexMaclean]

No description provided.

[llvmbot]

@llvm/pr-subscribers-backend-nvptx

@llvm/pr-subscribers-llvm-ir

Author: Alex MacLean (AlexMaclean)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/173097.diff

2 Files Affected:

• (modified) llvm/lib/IR/AutoUpgrade.cpp (+13-22)
• (modified) llvm/test/Assembler/auto_upgrade_nvvm_intrinsics.ll (+12-24)

diff --git a/llvm/lib/IR/AutoUpgrade.cpp b/llvm/lib/IR/AutoUpgrade.cpp
index 60505ac208c2c..9e4c5873e4ff8 100644
--- a/llvm/lib/IR/AutoUpgrade.cpp
+++ b/llvm/lib/IR/AutoUpgrade.cpp
@@ -1538,6 +1538,19 @@ static bool upgradeIntrinsicFunction1(Function *F, Function *&NewFn,
                                                     {F->getReturnType()});
           return true;
         }
+      } else if (F->arg_size() == 2) {
+        Intrinsic::ID IID =
+            StringSwitch<Intrinsic::ID>(Name)
+                .Cases({"max.s", "max.i", "max.ll"}, Intrinsic::smax)
+                .Cases({"min.s", "min.i", "min.ll"}, Intrinsic::smin)
+                .Cases({"max.us", "max.ui", "max.ull"}, Intrinsic::umax)
+                .Cases({"min.us", "min.ui", "min.ull"}, Intrinsic::umin)
+                .Default(Intrinsic::not_intrinsic);
+        if (IID != Intrinsic::not_intrinsic) {
+          NewFn = Intrinsic::getOrInsertDeclaration(F->getParent(), IID,
+                                                    {F->getReturnType()});
+          return true;
+        }
       }
 
       // Check for nvvm intrinsics that need a return type adjustment.
@@ -1581,10 +1594,6 @@ static bool upgradeIntrinsicFunction1(Function *F, Function *&NewFn,
         // nvvm.ex2.approx.{f,ftz.f,d,f16x2}
         Expand =
             Name == "f" || Name == "ftz.f" || Name == "d" || Name == "f16x2";
-      else if (Name.consume_front("max.") || Name.consume_front("min."))
-        // nvvm.{min,max}.{i,ii,ui,ull}
-        Expand = Name == "s" || Name == "i" || Name == "ll" || Name == "us" ||
-                 Name == "ui" || Name == "ull";
       else if (Name.consume_front("atomic.load."))
         // nvvm.atomic.load.add.{f32,f64}.p
         // nvvm.atomic.load.{inc,dec}.32.p
@@ -2649,24 +2658,6 @@ static Value *upgradeNVVMIntrinsicCall(StringRef Name, CallBase *CI,
                                                   : AtomicRMWInst::UDecWrap;
     Rep = Builder.CreateAtomicRMW(Op, Ptr, Val, MaybeAlign(),
                                   AtomicOrdering::SequentiallyConsistent);
-  } else if (Name.consume_front("max.") &&
-             (Name == "s" || Name == "i" || Name == "ll" || Name == "us" ||
-              Name == "ui" || Name == "ull")) {
-    Value *Arg0 = CI->getArgOperand(0);
-    Value *Arg1 = CI->getArgOperand(1);
-    Value *Cmp = Name.starts_with("u")
-                     ? Builder.CreateICmpUGE(Arg0, Arg1, "max.cond")
-                     : Builder.CreateICmpSGE(Arg0, Arg1, "max.cond");
-    Rep = Builder.CreateSelect(Cmp, Arg0, Arg1, "max");
-  } else if (Name.consume_front("min.") &&
-             (Name == "s" || Name == "i" || Name == "ll" || Name == "us" ||
-              Name == "ui" || Name == "ull")) {
-    Value *Arg0 = CI->getArgOperand(0);
-    Value *Arg1 = CI->getArgOperand(1);
-    Value *Cmp = Name.starts_with("u")
-                     ? Builder.CreateICmpULE(Arg0, Arg1, "min.cond")
-                     : Builder.CreateICmpSLE(Arg0, Arg1, "min.cond");
-    Rep = Builder.CreateSelect(Cmp, Arg0, Arg1, "min");
   } else if (Name == "clz.ll") {
     // llvm.nvvm.clz.ll returns an i32, but llvm.ctlz.i64 returns an i64.
     Value *Arg = CI->getArgOperand(0);
diff --git a/llvm/test/Assembler/auto_upgrade_nvvm_intrinsics.ll b/llvm/test/Assembler/auto_upgrade_nvvm_intrinsics.ll
index 0f749cf81f39b..4f07946e503c4 100644
--- a/llvm/test/Assembler/auto_upgrade_nvvm_intrinsics.ll
+++ b/llvm/test/Assembler/auto_upgrade_nvvm_intrinsics.ll
@@ -158,52 +158,40 @@ define void @tanh(float %a) {
 
 ; CHECK-LABEL: @min_max
 define void @min_max(i16 %a1, i16 %a2, i32 %b1, i32 %b2, i64 %c1, i64 %c2) {
-; CHECK: [[maxs:%[a-zA-Z0-9.]+]] = icmp sge i16 %a1, %a2
-; CHECK: select i1 [[maxs]], i16 %a1, i16 %a2
+; CHECK: %r1 = call i16 @llvm.smax.i16(i16 %a1, i16 %a2)
   %r1 = call i16 @llvm.nvvm.max.s(i16 %a1, i16 %a2)
 
-; CHECK: [[maxi:%[a-zA-Z0-9.]+]] = icmp sge i32 %b1, %b2
-; CHECK: select i1 [[maxi]], i32 %b1, i32 %b2
+; CHECK: %r2 = call i32 @llvm.smax.i32(i32 %b1, i32 %b2)
   %r2 = call i32 @llvm.nvvm.max.i(i32 %b1, i32 %b2)
 
-; CHECK: [[maxll:%[a-zA-Z0-9.]+]] = icmp sge i64 %c1, %c2
-; CHECK: select i1 [[maxll]], i64 %c1, i64 %c2
+; CHECK: %r3 = call i64 @llvm.smax.i64(i64 %c1, i64 %c2)
   %r3 = call i64 @llvm.nvvm.max.ll(i64 %c1, i64 %c2)
 
-; CHECK: [[maxus:%[a-zA-Z0-9.]+]] = icmp uge i16 %a1, %a2
-; CHECK: select i1 [[maxus]], i16 %a1, i16 %a2
+; CHECK: %r4 = call i16 @llvm.umax.i16(i16 %a1, i16 %a2)
   %r4 = call i16 @llvm.nvvm.max.us(i16 %a1, i16 %a2)
 
-; CHECK: [[maxui:%[a-zA-Z0-9.]+]] = icmp uge i32 %b1, %b2
-; CHECK: select i1 [[maxui]], i32 %b1, i32 %b2
+; CHECK: %r5 = call i32 @llvm.umax.i32(i32 %b1, i32 %b2)
   %r5 = call i32 @llvm.nvvm.max.ui(i32 %b1, i32 %b2)
 
-; CHECK: [[maxull:%[a-zA-Z0-9.]+]] = icmp uge i64 %c1, %c2
-; CHECK: select i1 [[maxull]], i64 %c1, i64 %c2
+; CHECK: %r6 = call i64 @llvm.umax.i64(i64 %c1, i64 %c2)
   %r6 = call i64 @llvm.nvvm.max.ull(i64 %c1, i64 %c2)
 
-; CHECK: [[mins:%[a-zA-Z0-9.]+]] = icmp sle i16 %a1, %a2
-; CHECK: select i1 [[mins]], i16 %a1, i16 %a2
+; CHECK: %r7 = call i16 @llvm.smin.i16(i16 %a1, i16 %a2)
   %r7 = call i16 @llvm.nvvm.min.s(i16 %a1, i16 %a2)
 
-; CHECK: [[mini:%[a-zA-Z0-9.]+]] = icmp sle i32 %b1, %b2
-; CHECK: select i1 [[mini]], i32 %b1, i32 %b2
+; CHECK: %r8 = call i32 @llvm.smin.i32(i32 %b1, i32 %b2)
   %r8 = call i32 @llvm.nvvm.min.i(i32 %b1, i32 %b2)
 
-; CHECK: [[minll:%[a-zA-Z0-9.]+]] = icmp sle i64 %c1, %c2
-; CHECK: select i1 [[minll]], i64 %c1, i64 %c2
+; CHECK: %r9 = call i64 @llvm.smin.i64(i64 %c1, i64 %c2)
   %r9 = call i64 @llvm.nvvm.min.ll(i64 %c1, i64 %c2)
 
-; CHECK: [[minus:%[a-zA-Z0-9.]+]] = icmp ule i16 %a1, %a2
-; CHECK: select i1 [[minus]], i16 %a1, i16 %a2
+; CHECK: %r10 = call i16 @llvm.umin.i16(i16 %a1, i16 %a2)
   %r10 = call i16 @llvm.nvvm.min.us(i16 %a1, i16 %a2)
 
-; CHECK: [[minui:%[a-zA-Z0-9.]+]] = icmp ule i32 %b1, %b2
-; CHECK: select i1 [[minui]], i32 %b1, i32 %b2
+; CHECK: %r11 = call i32 @llvm.umin.i32(i32 %b1, i32 %b2)
   %r11 = call i32 @llvm.nvvm.min.ui(i32 %b1, i32 %b2)
 
-; CHECK: [[minull:%[a-zA-Z0-9.]+]] = icmp ule i64 %c1, %c2
-; CHECK: select i1 [[minull]], i64 %c1, i64 %c2
+; CHECK: %r12 = call i64 @llvm.umin.i64(i64 %c1, i64 %c2)
   %r12 = call i64 @llvm.nvvm.min.ull(i64 %c1, i64 %c2)
 
   ret void