[PATCH] D99034: GlobalISel: Constant fold integer min/max opcodes

[Matt Arsenault via Phabricator via llvm-commits]

arsenm created this revision.
arsenm added reviewers: aemerson, paquette, dsanders, aditya_nandakumar, bogner.
Herald added subscribers: kerbowa, hiraditya, rovka, nhaehnle, jvesely.
arsenm requested review of this revision.
Herald added a subscriber: wdng.
Herald added a project: LLVM.

https://reviews.llvm.org/D99034

Files:
  llvm/lib/CodeGen/GlobalISel/CSEMIRBuilder.cpp
  llvm/lib/CodeGen/GlobalISel/Utils.cpp
  llvm/test/CodeGen/AMDGPU/GlobalISel/combine-fold-binop-into-select.mir


Index: llvm/test/CodeGen/AMDGPU/GlobalISel/combine-fold-binop-into-select.mir
===================================================================
--- llvm/test/CodeGen/AMDGPU/GlobalISel/combine-fold-binop-into-select.mir
+++ llvm/test/CodeGen/AMDGPU/GlobalISel/combine-fold-binop-into-select.mir
@@ -910,10 +910,7 @@
     ; CHECK: %cond:_(s1) = G_ICMP intpred(eq), %reg(s32), %zero
     ; CHECK: %ten:_(s32) = G_CONSTANT i32 10
     ; CHECK: %twenty:_(s32) = G_CONSTANT i32 20
-    ; CHECK: %thirty:_(s32) = G_CONSTANT i32 30
-    ; CHECK: [[SMIN:%[0-9]+]]:_(s32) = G_SMIN %ten, %thirty
-    ; CHECK: [[SMIN1:%[0-9]+]]:_(s32) = G_SMIN %twenty, %thirty
-    ; CHECK: %smin:_(s32) = G_SELECT %cond(s1), [[SMIN]], [[SMIN1]]
+    ; CHECK: %smin:_(s32) = G_SELECT %cond(s1), %ten, %twenty
     ; CHECK: S_ENDPGM 0, implicit %smin(s32)
     %reg:_(s32) = COPY $vgpr0
     %zero:_(s32) = G_CONSTANT i32 0
@@ -934,16 +931,8 @@
     liveins: $vgpr0
     ; CHECK-LABEL: name: fold_smax_into_select_s32_0
     ; CHECK: liveins: $vgpr0
-    ; CHECK: %reg:_(s32) = COPY $vgpr0
-    ; CHECK: %zero:_(s32) = G_CONSTANT i32 0
-    ; CHECK: %cond:_(s1) = G_ICMP intpred(eq), %reg(s32), %zero
-    ; CHECK: %ten:_(s32) = G_CONSTANT i32 10
-    ; CHECK: %twenty:_(s32) = G_CONSTANT i32 20
     ; CHECK: %thirty:_(s32) = G_CONSTANT i32 30
-    ; CHECK: [[SMAX:%[0-9]+]]:_(s32) = G_SMAX %ten, %thirty
-    ; CHECK: [[SMAX1:%[0-9]+]]:_(s32) = G_SMAX %twenty, %thirty
-    ; CHECK: %smax:_(s32) = G_SELECT %cond(s1), [[SMAX]], [[SMAX1]]
-    ; CHECK: S_ENDPGM 0, implicit %smax(s32)
+    ; CHECK: S_ENDPGM 0, implicit %thirty(s32)
     %reg:_(s32) = COPY $vgpr0
     %zero:_(s32) = G_CONSTANT i32 0
     %cond:_(s1) = G_ICMP intpred(eq), %reg, %zero
@@ -968,10 +957,7 @@
     ; CHECK: %cond:_(s1) = G_ICMP intpred(eq), %reg(s32), %zero
     ; CHECK: %ten:_(s32) = G_CONSTANT i32 10
     ; CHECK: %twenty:_(s32) = G_CONSTANT i32 20
-    ; CHECK: %thirty:_(s32) = G_CONSTANT i32 30
-    ; CHECK: [[UMIN:%[0-9]+]]:_(s32) = G_UMIN %ten, %thirty
-    ; CHECK: [[UMIN1:%[0-9]+]]:_(s32) = G_UMIN %twenty, %thirty
-    ; CHECK: %umin:_(s32) = G_SELECT %cond(s1), [[UMIN]], [[UMIN1]]
+    ; CHECK: %umin:_(s32) = G_SELECT %cond(s1), %ten, %twenty
     ; CHECK: S_ENDPGM 0, implicit %umin(s32)
     %reg:_(s32) = COPY $vgpr0
     %zero:_(s32) = G_CONSTANT i32 0
@@ -992,16 +978,8 @@
     liveins: $vgpr0
     ; CHECK-LABEL: name: fold_umax_into_select_s32_0
     ; CHECK: liveins: $vgpr0
-    ; CHECK: %reg:_(s32) = COPY $vgpr0
-    ; CHECK: %zero:_(s32) = G_CONSTANT i32 0
-    ; CHECK: %cond:_(s1) = G_ICMP intpred(eq), %reg(s32), %zero
-    ; CHECK: %ten:_(s32) = G_CONSTANT i32 10
-    ; CHECK: %twenty:_(s32) = G_CONSTANT i32 20
     ; CHECK: %thirty:_(s32) = G_CONSTANT i32 30
-    ; CHECK: [[UMAX:%[0-9]+]]:_(s32) = G_UMAX %ten, %thirty
-    ; CHECK: [[UMAX1:%[0-9]+]]:_(s32) = G_UMAX %twenty, %thirty
-    ; CHECK: %umax:_(s32) = G_SELECT %cond(s1), [[UMAX]], [[UMAX1]]
-    ; CHECK: S_ENDPGM 0, implicit %umax(s32)
+    ; CHECK: S_ENDPGM 0, implicit %thirty(s32)
     %reg:_(s32) = COPY $vgpr0
     %zero:_(s32) = G_CONSTANT i32 0
     %cond:_(s1) = G_ICMP intpred(eq), %reg, %zero
Index: llvm/lib/CodeGen/GlobalISel/Utils.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/Utils.cpp
+++ llvm/lib/CodeGen/GlobalISel/Utils.cpp
@@ -477,6 +477,14 @@
     if (!C2.getBoolValue())
       break;
     return C1.srem(C2);
+  case TargetOpcode::G_SMIN:
+    return APIntOps::smin(C1, C2);
+  case TargetOpcode::G_SMAX:
+    return APIntOps::smax(C1, C2);
+  case TargetOpcode::G_UMIN:
+    return APIntOps::umin(C1, C2);
+  case TargetOpcode::G_UMAX:
+    return APIntOps::umax(C1, C2);
   }
 
   return None;
Index: llvm/lib/CodeGen/GlobalISel/CSEMIRBuilder.cpp
===================================================================
--- llvm/lib/CodeGen/GlobalISel/CSEMIRBuilder.cpp
+++ llvm/lib/CodeGen/GlobalISel/CSEMIRBuilder.cpp
@@ -184,7 +184,11 @@
   case TargetOpcode::G_UDIV:
   case TargetOpcode::G_SDIV:
   case TargetOpcode::G_UREM:
-  case TargetOpcode::G_SREM: {
+  case TargetOpcode::G_SREM:
+  case TargetOpcode::G_SMIN:
+  case TargetOpcode::G_SMAX:
+  case TargetOpcode::G_UMIN:
+  case TargetOpcode::G_UMAX: {
     // Try to constant fold these.
     assert(SrcOps.size() == 2 && "Invalid sources");
     assert(DstOps.size() == 1 && "Invalid dsts");


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