[GlobalIsel][X86] Legalize G_FREEZE

[RKSimon]

llvm/lib/Target/X86/X86LegalizerInfo.cpp

342

copy -> freeze?

347

Why do you need the second type idx?

llvm/test/CodeGen/X86/GlobalISel/legalize-freeze.mir

3

Add 32-bit test coverage as well

[arsenm]

llvm/lib/Target/X86/X86LegalizerInfo.cpp

342

Don't see the point of the comment if it just restates freeze. For those who don't know freeze, something stating it's just a copy kind of makes sense

347

freeze only has one

[tschuett]

• remove comment, it was inspired by AArch64
• remove second type index
• 32-bit test coverage does not work yet. The legalizer still has some gaps.

llvm/lib/Target/X86/X86LegalizerInfo.cpp

X86LegalizerInfo::X86LegalizerInfo(const X86Subtarget &STI,
   // todo: vectors and address spaces
   getActionDefinitionsBuilder(G_SELECT)
        .legalFor({{s8, s32}, {s16, s32}, {s32, s32}, {s64, s32},
                   {p0, s32}})
     .widenScalarToNextPow2(0, /*Min=*/8)
     .clampScalar(0, s8, sMaxScalar)
     .clampScalar(1, s32, s32);
 
   // memory intrinsics
   getActionDefinitionsBuilder({G_MEMCPY, G_MEMMOVE, G_MEMSET}).libcall();
 
   // fp intrinsics
   getActionDefinitionsBuilder(G_INTRINSIC_ROUNDEVEN)
       .scalarize(0)
       .minScalar(0, LLT::scalar(32))
       .libcall();
 
+  getActionDefinitionsBuilder(G_FREEZE)
+    .legalFor({s8, s16, s32, s64, p0})
+    .widenScalarToNextPow2(0, /*Min=*/8)
+    .clampScalar(0, s8, sMaxScalar);
+
   setLegalizerInfo32bit();
   setLegalizerInfo64bit();
   setLegalizerInfoSSE1();
   setLegalizerInfoSSE2();
   setLegalizerInfoAVX();
   setLegalizerInfoAVX2();
   setLegalizerInfoAVX512();
 

llvm/test/CodeGen/X86/GlobalISel/legalize-freeze.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py UTC_ARGS: --version 2
+# RUN: llc -verify-machineinstrs -mtriple=x86_64-linux-gnu -run-pass=legalizer %s -o - | FileCheck %s
+
+# test freeze
+
+...
+---
+name:            test_freezep0
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_freezep0
+    ; CHECK: [[DEF:%[0-9]+]]:_(p0) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(p0) = G_FREEZE [[DEF]]
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(p0) = COPY [[FREEZE]](p0)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](p0)
+    %0:_(p0) = IMPLICIT_DEF
+    %1:_(p0) = G_FREEZE %0
+    %2:_(p0) = COPY %1(p0)
+    RET 0, implicit %2
+
+...
+---
+name:            test_freeze64
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_freeze64
+    ; CHECK: [[DEF:%[0-9]+]]:_(s64) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s64) = G_FREEZE [[DEF]]
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s64) = COPY [[FREEZE]](s64)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s64)
+    %0:_(s64) = IMPLICIT_DEF
+    %1:_(s64) = G_FREEZE %0
+    %2:_(s64) = COPY %1(s64)
+    RET 0, implicit %2
+
+...
+---
+name:            test_freeze48
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_freeze48
+    ; CHECK: [[DEF:%[0-9]+]]:_(s48) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[ANYEXT:%[0-9]+]]:_(s64) = G_ANYEXT [[DEF]](s48)
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s64) = G_FREEZE [[ANYEXT]]
+    ; CHECK-NEXT: [[TRUNC:%[0-9]+]]:_(s48) = G_TRUNC [[FREEZE]](s64)
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s48) = COPY [[TRUNC]](s48)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s48)
+    %0:_(s48) = IMPLICIT_DEF
+    %1:_(s48) = G_FREEZE %0
+    %2:_(s48) = COPY %1(s48)
+    RET 0, implicit %2
+
+...
+---
+name:            test_freeze32
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_freeze32
+    ; CHECK: [[DEF:%[0-9]+]]:_(s32) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s32) = G_FREEZE [[DEF]]
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s32) = COPY [[FREEZE]](s32)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s32)
+    %0:_(s32) = IMPLICIT_DEF
+    %1:_(s32) = G_FREEZE %0
+    %2:_(s32) = COPY %1(s32)
+    RET 0, implicit %2
+
+...
+---
+name:            test_freeze16
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_freeze16
+    ; CHECK: [[DEF:%[0-9]+]]:_(s16) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s16) = G_FREEZE [[DEF]]
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s16) = COPY [[FREEZE]](s16)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s16)
+    %0:_(s16) = IMPLICIT_DEF
+    %1:_(s16) = G_FREEZE %0
+    %2:_(s16) = COPY %1(s16)
+    RET 0, implicit %2
+
+...
+---
+name:            test_freeze8
+body:             |
+  bb.1:
+    ; CHECK-LABEL: name: test_freeze8
+    ; CHECK: [[DEF:%[0-9]+]]:_(s8) = IMPLICIT_DEF
+    ; CHECK-NEXT: [[FREEZE:%[0-9]+]]:_(s8) = G_FREEZE [[DEF]]
+    ; CHECK-NEXT: [[COPY:%[0-9]+]]:_(s8) = COPY [[FREEZE]](s8)
+    ; CHECK-NEXT: RET 0, implicit [[COPY]](s8)
+    %0:_(s8) = IMPLICIT_DEF
+    %1:_(s8) = G_FREEZE %0
+    %2:_(s8) = COPY %1(s8)
+    RET 0, implicit %2
+
+...