[GlobalISel][X86] extend G_ZEXT support.

[igorb]

Summary

Mark G_ZEXT/G_SEXT i1 to i8/i16, i8 to i16 as legal.
Support G_ZEXT i1 to i8/i16 instruction selection ( C++ code).
This patch requred to support G_LOAD/G_STORE i1.

[guyblank]

LGTM

lib/Target/X86/X86InstructionSelector.cpp

if (I.getOpcode() != TargetOpcode::G_ZEXT)
     return false;
 
   const unsigned DstReg = I.getOperand(0).getReg();
   const unsigned SrcReg = I.getOperand(1).getReg();
 
   const LLT DstTy = MRI.getType(DstReg);
   const LLT SrcTy = MRI.getType(SrcReg);
 
-  if (SrcTy == LLT::scalar(1)) {
+  if (SrcTy != LLT::scalar(1))
+    return false;
 
-    unsigned AndOpc;
-    if (DstTy == LLT::scalar(32))
-      AndOpc = X86::AND32ri8;
-    else if (DstTy == LLT::scalar(64))
-      AndOpc = X86::AND64ri8;
-    else
-      return false;
+  if (DstTy == LLT::scalar(8))
+    AndOpc = X86::AND8ri8;
+  else if (DstTy == LLT::scalar(16))
+    AndOpc = X86::AND16ri8;
+  else if (DstTy == LLT::scalar(32))
 
-    unsigned DefReg =
-        MRI.createVirtualRegister(getRegClass(DstTy, DstReg, MRI));
-
+  unsigned DefReg = SrcReg;
+  if (DstTy != LLT::scalar(8)) {
+    DefReg = MRI.createVirtualRegister(getRegClass(DstTy, DstReg, MRI));
     BuildMI(*I.getParent(), I, I.getDebugLoc(),
             TII.get(TargetOpcode::SUBREG_TO_REG), DefReg)
         .addImm(0)
         .addReg(SrcReg)
         .addImm(X86::sub_8bit);
+  }
 
-    MachineInstr &AndInst =
-        *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(AndOpc), DstReg)
-             .addReg(DefReg)
-             .addImm(1);
 
-    constrainSelectedInstRegOperands(AndInst, TII, TRI, RBI);
 
-    I.eraseFromParent();
-    return true;
-  }
 
-  return false;
-}
-
 bool X86InstructionSelector::selectCmp(MachineInstr &I,
                                        MachineRegisterInfo &MRI,
                                        MachineFunction &MF) const {
   if (I.getOpcode() != TargetOpcode::G_ICMP)
     return false;
 
   X86::CondCode CC;
   bool SwapArgs;

lib/Target/X86/X86LegalizerInfo.cpp

void X86LegalizerInfo::setLegalizerInfo32bit() {
   // Constants
   for (auto Ty : {s8, s16, s32, p0})
     setAction({TargetOpcode::G_CONSTANT, Ty}, Legal);
 
   setAction({TargetOpcode::G_CONSTANT, s1}, WidenScalar);
   setAction({TargetOpcode::G_CONSTANT, s64}, NarrowScalar);
 
   // Extensions
-  setAction({G_ZEXT, s32}, Legal);
-  setAction({G_SEXT, s32}, Legal);
+  for (auto Ty : {s8, s16, s32}) {
+    setAction({G_ZEXT, Ty}, Legal);
+    setAction({G_SEXT, Ty}, Legal);
+  }
 
   for (auto Ty : {s1, s8, s16}) {
     setAction({G_ZEXT, 1, Ty}, Legal);
     setAction({G_SEXT, 1, Ty}, Legal);
   }
 
   // Comparison
   setAction({G_ICMP, s1}, Legal);
void X86LegalizerInfo::setLegalizerInfo64bit() {
 
   // Constants
   for (auto Ty : {s8, s16, s32, s64, p0})
     setAction({TargetOpcode::G_CONSTANT, Ty}, Legal);
 
   setAction({TargetOpcode::G_CONSTANT, s1}, WidenScalar);
 
   // Extensions
-  for (auto Ty : {s32, s64}) {
+  for (auto Ty : {s8, s16, s32, s64}) {
     setAction({G_ZEXT, Ty}, Legal);
     setAction({G_SEXT, Ty}, Legal);
   }
 
   for (auto Ty : {s1, s8, s16, s32}) {
     setAction({G_ZEXT, 1, Ty}, Legal);
     setAction({G_SEXT, 1, Ty}, Legal);
   }

test/CodeGen/X86/GlobalISel/ext.ll

 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
 ; RUN: llc -mtriple=x86_64-linux-gnu    -global-isel -verify-machineinstrs < %s -o - | FileCheck %s --check-prefix=X64
 ; RUN: llc -mtriple=i386-linux-gnu      -global-isel -verify-machineinstrs < %s -o - | FileCheck %s --check-prefix=X32
 
+define i8 @test_zext_i1toi8(i32 %a) {
+; X64-LABEL: test_zext_i1toi8:
+; X64:       # BB#0:
+; X64-NEXT:    andb $1, %dil
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    retq
+;
+; X32-LABEL: test_zext_i1toi8:
+; X32:       # BB#0:
+; X32-NEXT:    movl 4(%esp), %eax
+; X32-NEXT:    andb $1, %al
+; X32-NEXT:    # kill: %AL<def> %AL<kill> %EAX<kill>
+; X32-NEXT:    retl
+  %val = trunc i32 %a to i1
+  %r = zext i1 %val to i8
+  ret i8 %r
+}
+
+define i16 @test_zext_i1toi16(i32 %a) {
+; X64-LABEL: test_zext_i1toi16:
+; X64:       # BB#0:
+; X64-NEXT:    andw $1, %di
+; X64-NEXT:    movl %edi, %eax
+; X64-NEXT:    retq
+;
+; X32-LABEL: test_zext_i1toi16:
+; X32:       # BB#0:
+; X32-NEXT:    movl 4(%esp), %eax
+; X32-NEXT:    andw $1, %ax
+; X32-NEXT:    # kill: %AX<def> %AX<kill> %EAX<kill>
+; X32-NEXT:    retl
+  %val = trunc i32 %a to i1
+  %r = zext i1 %val to i16
+  ret i16 %r
+}
+
 define i32 @test_zext_i1(i32 %a) {
 ; X64-LABEL: test_zext_i1:
 ; X64:       # BB#0:
 ; X64-NEXT:    andl $1, %edi
 ; X64-NEXT:    movl %edi, %eax
 ; X64-NEXT:    retq
 ;
 ; X32-LABEL: test_zext_i1:

test/CodeGen/X86/GlobalISel/legalize-ext.mir

 # RUN: llc -mtriple=i386-linux-gnu   -global-isel -run-pass=legalizer %s -o - | FileCheck %s --check-prefix=ALL --check-prefix=X32
 # RUN: llc -mtriple=x86_64-linux-gnu -global-isel -run-pass=legalizer %s -o - | FileCheck %s --check-prefix=ALL --check-prefix=X64
 --- |
+
+  define i8 @test_zext_i1toi8(i1 %a) {
+    %r = zext i1 %a to i8
+    ret i8 %r
+  }
+
+  define i16 @test_zext_i1toi16(i1 %a) {
+    %r = zext i1 %a to i16
+    ret i16 %r
+  }
+
   define i32 @test_zext_i1(i8 %a) {
     %val = trunc i8 %a to i1
     %r = zext i1 %val to i32
     ret i32 %r
   }
 
+  define i16 @test_zext_i8toi16(i8 %val) {
+    %r = zext i8 %val to i16
+    ret i16 %r
+  }
+
   define i32 @test_zext_i8(i8 %val) {
     %r = zext i8 %val to i32
     ret i32 %r
   }
 
   define i32 @test_zext_i16(i16 %val) {
     %r = zext i16 %val to i32
     ret i32 %r
   }
 
+  define i8 @test_sext_i1toi8(i1 %a) {
+    %r = sext i1 %a to i8
+    ret i8 %r
+  }
+
+  define i16 @test_sext_i1toi16(i1 %a) {
+    %r = sext i1 %a to i16
+    ret i16 %r
+  }
+
   define i32 @test_sext_i1(i8 %a) {
     %val = trunc i8 %a to i1
     %r = sext i1 %val to i32
     ret i32 %r
   }
 
+  define i16 @test_sext_i8toi16(i8 %val) {
+    %r = sext i8 %val to i16
+    ret i16 %r
+  }
+
   define i32 @test_sext_i8(i8 %val) {
     %r = sext i8 %val to i32
     ret i32 %r
   }
 
   define i32 @test_sext_i16(i16 %val) {
     %r = sext i16 %val to i32
     ret i32 %r
   }
 
 ...
 ---
+name:            test_zext_i1toi8
+# ALL-LABEL: name:  test_zext_i1toi8
+alignment:       4
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+# ALL:          %0(s1) = COPY %edi
+# ALL-NEXT:     %1(s8) = G_ZEXT %0(s1)
+# ALL-NEXT:     %al = COPY %1(s8)
+# ALL-NEXT:     RET 0, implicit %al
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: %edi
+
+    %0(s1) = COPY %edi
+    %1(s8) = G_ZEXT %0(s1)
+    %al = COPY %1(s8)
+    RET 0, implicit %al
+
+...
+---
+name:            test_zext_i1toi16
+# ALL-LABEL: name:  test_zext_i1toi16
+alignment:       4
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+# ALL:          %0(s1) = COPY %edi
+# ALL-NEXT:     %1(s16) = G_ZEXT %0(s1)
+# ALL-NEXT:     %ax = COPY %1(s16)
+# ALL-NEXT:     RET 0, implicit %ax
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: %edi
+
+    %0(s1) = COPY %edi
+    %1(s16) = G_ZEXT %0(s1)
+    %ax = COPY %1(s16)
+    RET 0, implicit %ax
+
+...
+---
 name:            test_zext_i1
 # ALL-LABEL: name:  test_zext_i1
 alignment:       4
 legalized:       false
 regBankSelected: false
 registers:
   - { id: 0, class: _ }
   - { id: 1, class: _ }
bb.1 (%ir-block.0):
     %0(s8) = COPY %edi
     %1(s1) = G_TRUNC %0(s8)
     %2(s32) = G_ZEXT %1(s1)
     %eax = COPY %2(s32)
     RET 0, implicit %eax
 
 ...
 ---
+name:            test_zext_i8toi16
+# ALL-LABEL: name:  test_zext_i8toi16
+alignment:       4
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+# ALL:          %0(s8) = COPY %edi
+# ALL-NEXT:     %1(s16) = G_ZEXT %0(s8)
+# ALL-NEXT:     %ax = COPY %1(s16)
+# ALL-NEXT:     RET 0, implicit %ax
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: %edi
+
+    %0(s8) = COPY %edi
+    %1(s16) = G_ZEXT %0(s8)
+    %ax = COPY %1(s16)
+    RET 0, implicit %ax
+
+...
+---
 name:            test_zext_i8
 # ALL-LABEL: name:  test_zext_i8
 alignment:       4
 legalized:       false
 regBankSelected: false
 registers:
   - { id: 0, class: _ }
   - { id: 1, class: _ }
bb.1 (%ir-block.0):
 
     %0(s16) = COPY %edi
     %1(s32) = G_ZEXT %0(s16)
     %eax = COPY %1(s32)
     RET 0, implicit %eax
 
 ...
 ---
+name:            test_sext_i1toi8
+# ALL-LABEL: name:  test_sext_i1toi8
+alignment:       4
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+# ALL:          %0(s1) = COPY %edi
+# ALL-NEXT:     %1(s8) = G_SEXT %0(s1)
+# ALL-NEXT:     %al = COPY %1(s8)
+# ALL-NEXT:     RET 0, implicit %al
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: %edi
+
+    %0(s1) = COPY %edi
+    %1(s8) = G_SEXT %0(s1)
+    %al = COPY %1(s8)
+    RET 0, implicit %al
+
+...
+---
+name:            test_sext_i1toi16
+# ALL-LABEL: name:  test_sext_i1toi16
+alignment:       4
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+# ALL:          %0(s1) = COPY %edi
+# ALL-NEXT:     %1(s16) = G_SEXT %0(s1)
+# ALL-NEXT:     %ax = COPY %1(s16)
+# ALL-NEXT:     RET 0, implicit %ax
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: %edi
+
+    %0(s1) = COPY %edi
+    %1(s16) = G_SEXT %0(s1)
+    %ax = COPY %1(s16)
+    RET 0, implicit %ax
+
+...
+---
 name:            test_sext_i1
 # ALL-LABEL: name:  test_sext_i1
 alignment:       4
 legalized:       false
 regBankSelected: false
 registers:
   - { id: 0, class: _ }
   - { id: 1, class: _ }
bb.1 (%ir-block.0):
     %0(s8) = COPY %edi
     %1(s1) = G_TRUNC %0(s8)
     %2(s32) = G_SEXT %1(s1)
     %eax = COPY %2(s32)
     RET 0, implicit %eax
 
 ...
 ---
+name:            test_sext_i8toi16
+# ALL-LABEL: name:  test_sext_i8toi16
+alignment:       4
+legalized:       false
+regBankSelected: false
+registers:
+  - { id: 0, class: _, preferred-register: '' }
+  - { id: 1, class: _, preferred-register: '' }
+# ALL:          %0(s8) = COPY %edi
+# ALL-NEXT:     %1(s16) = G_SEXT %0(s8)
+# ALL-NEXT:     %ax = COPY %1(s16)
+# ALL-NEXT:     RET 0, implicit %ax
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: %edi
+
+    %0(s8) = COPY %edi
+    %1(s16) = G_SEXT %0(s8)
+    %ax = COPY %1(s16)
+    RET 0, implicit %ax
+
+...
+---
 name:            test_sext_i8
 # ALL-LABEL: name:  test_sext_i8
 alignment:       4
 legalized:       false
 regBankSelected: false
 registers:
   - { id: 0, class: _ }
   - { id: 1, class: _ }

test/CodeGen/X86/GlobalISel/select-ext.mir

 # RUN: llc -mtriple=i386-linux-gnu   -global-isel -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s --check-prefix=ALL --check-prefix=X32
 # RUN: llc -mtriple=x86_64-linux-gnu -global-isel -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s --check-prefix=ALL --check-prefix=X64
 
 --- |
+  define i8 @test_zext_i1toi8(i1 %a) {
+    %r = zext i1 %a to i8
+    ret i8 %r
+  }
+
+  define i16 @test_zext_i1toi16(i1 %a) {
+    %r = zext i1 %a to i16
+    ret i16 %r
+  }
+
   define i32 @test_zext_i1(i1 %a) {
     %r = zext i1 %a to i32
     ret i32 %r
   }
 
   define i32 @test_zext_i8(i8 %val) {
     %r = zext i8 %val to i32
     ret i32 %r
--- |
 
   define i32 @test_sext_i16(i16 %val) {
     %r = sext i16 %val to i32
     ret i32 %r
   }
 
 ...
 ---
+name:            test_zext_i1toi8
+# ALL-LABEL: name:  test_zext_i1toi8
+alignment:       4
+legalized:       true
+regBankSelected: true
+# ALL:      registers:
+# ALL-NEXT:   - { id: 0, class: gr8, preferred-register: '' }
+# ALL-NEXT:   - { id: 1, class: gr8, preferred-register: '' }
+registers:
+  - { id: 0, class: gpr, preferred-register: '' }
+  - { id: 1, class: gpr, preferred-register: '' }
+# ALL:          %0 = COPY %dil
+# ALL-NEXT:     %1 = AND8ri8 %0, 1, implicit-def %eflags
+# ALL-NEXT:     %al = COPY %1
+# ALL-NEXT:     RET 0, implicit %al
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: %edi
+
+    %0(s1) = COPY %edi
+    %1(s8) = G_ZEXT %0(s1)
+    %al = COPY %1(s8)
+    RET 0, implicit %al
+
+...
+---
+name:            test_zext_i1toi16
+# ALL-LABEL: name:  test_zext_i1toi16
+alignment:       4
+legalized:       true
+regBankSelected: true
+# ALL:      registers:
+# ALL-NEXT:   - { id: 0, class: gr8, preferred-register: '' }
+# ALL-NEXT:   - { id: 1, class: gr16, preferred-register: '' }
+# ALL-NEXT:   - { id: 2, class: gr16, preferred-register: '' }
+registers:
+  - { id: 0, class: gpr, preferred-register: '' }
+  - { id: 1, class: gpr, preferred-register: '' }
+# ALL:          %0 = COPY %dil
+# ALL-NEXT:     %2 = SUBREG_TO_REG 0, %0, 1
+# ALL-NEXT:     %1 = AND16ri8 %2, 1, implicit-def %eflags
+# ALL-NEXT:     %ax = COPY %1
+# ALL-NEXT:     RET 0, implicit %ax
+body:             |
+  bb.1 (%ir-block.0):
+    liveins: %edi
+
+    %0(s1) = COPY %edi
+    %1(s16) = G_ZEXT %0(s1)
+    %ax = COPY %1(s16)
+    RET 0, implicit %ax
+
+...
+---
 name:            test_zext_i1
 # ALL-LABEL: name:  test_zext_i1
 alignment:       4
 legalized:       true
 regBankSelected: true
 # ALL:      registers:
 # ALL-NEXT:   - { id: 0, class: gr8, preferred-register: '' }
 # ALL-NEXT:   - { id: 1, class: gr32, preferred-register: '' }