[X86][GlobalIsel] Adds support for G_UMIN/G_UMAX/G_SMIN/G_SMAX (#161783)

Original PR broke in rebase
#160247. Continuing here
This patch adds support for G_[U|S][MIN|MAX] opcodes into X86 Target.

This PR addressed review comments
1. About Widening to next power of 2
#160247 (comment)
2. clamping scalar
#160247 (comment)

Author: mahesh-attarde

llvm/lib/Target/X86/GISel/X86LegalizerInfo.cpp

@@ -149,6 +149,10 @@ X86LegalizerInfo::X86LegalizerInfo(const X86Subtarget &STI,
         });
   }
 
+  getActionDefinitionsBuilder({G_UMIN, G_UMAX, G_SMIN, G_SMAX})
+      .widenScalarToNextPow2(0, /*Min=*/32)
+      .lower();
+
   // integer addition/subtraction
   getActionDefinitionsBuilder({G_ADD, G_SUB})
       .legalFor({s8, s16, s32})

llvm/test/CodeGen/X86/isel-smax.ll

@@ -1,19 +1,19 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
-; RUN: llc < %s -mtriple=x86_64-linux-gnu | FileCheck %s --check-prefixes=X64
-; RUN: llc < %s -mtriple=x86_64-linux-gnu -fast-isel | FileCheck %s --check-prefixes=FASTISEL-X64
-; RUN: llc < %s -mtriple=x86_64-linux-gnu -global-isel -global-isel-abort=2 | FileCheck %s --check-prefixes=X64
-; RUN: llc < %s -mtriple=i686-linux-gnu | FileCheck %s --check-prefixes=X86
-; RUN: llc < %s -mtriple=i686-linux-gnu -fast-isel | FileCheck %s --check-prefixes=FASTISEL-X86
-; RUN: llc < %s -mtriple=i686-linux-gnu -global-isel -global-isel-abort=2 | FileCheck %s --check-prefixes=X86
+; RUN: llc < %s -mtriple=x86_64-linux-gnu | FileCheck %s --check-prefixes=X64,DAG-X64
+; RUN: llc < %s -mtriple=x86_64-linux-gnu -fast-isel | FileCheck %s --check-prefixes=X64,FASTISEL-X64
+; RUN: llc < %s -mtriple=x86_64-linux-gnu -global-isel -global-isel-abort=1 | FileCheck %s --check-prefixes=GISEL-X64
+; RUN: llc < %s -mtriple=i686-linux-gnu | FileCheck %s --check-prefixes=X86,DAG-X86
+; RUN: llc < %s -mtriple=i686-linux-gnu -fast-isel | FileCheck %s --check-prefixes=X86,FASTISEL-X86
+; RUN: llc < %s -mtriple=i686-linux-gnu -global-isel -global-isel-abort=1 | FileCheck %s --check-prefixes=GISEL-X86
 
 define i8 @smax_i8(i8 %a, i8 %b) nounwind readnone {
-; X64-LABEL: smax_i8:
-; X64:       # %bb.0:
-; X64-NEXT:    movl %esi, %eax
-; X64-NEXT:    cmpb %al, %dil
-; X64-NEXT:    cmovgl %edi, %eax
-; X64-NEXT:    # kill: def $al killed $al killed $eax
-; X64-NEXT:    retq
+; DAG-X64-LABEL: smax_i8:
+; DAG-X64:       # %bb.0:
+; DAG-X64-NEXT:    movl %esi, %eax
+; DAG-X64-NEXT:    cmpb %al, %dil
+; DAG-X64-NEXT:    cmovgl %edi, %eax
+; DAG-X64-NEXT:    # kill: def $al killed $al killed $eax
+; DAG-X64-NEXT:    retq
 ;
 ; FASTISEL-X64-LABEL: smax_i8:
 ; FASTISEL-X64:       # %bb.0:
@@ -24,6 +24,17 @@ define i8 @smax_i8(i8 %a, i8 %b) nounwind readnone {
 ; FASTISEL-X64-NEXT:    # kill: def $al killed $al killed $eax
 ; FASTISEL-X64-NEXT:    retq
 ;
+; GISEL-X64-LABEL: smax_i8:
+; GISEL-X64:       # %bb.0:
+; GISEL-X64-NEXT:    movl %esi, %eax
+; GISEL-X64-NEXT:    xorl %ecx, %ecx
+; GISEL-X64-NEXT:    cmpb %al, %dil
+; GISEL-X64-NEXT:    setg %cl
+; GISEL-X64-NEXT:    andl $1, %ecx
+; GISEL-X64-NEXT:    cmovnew %di, %ax
+; GISEL-X64-NEXT:    # kill: def $al killed $al killed $eax
+; GISEL-X64-NEXT:    retq
+;
 ; X86-LABEL: smax_i8:
 ; X86:       # %bb.0:
 ; X86-NEXT:    movzbl {{[0-9]+}}(%esp), %ecx
@@ -35,16 +46,20 @@ define i8 @smax_i8(i8 %a, i8 %b) nounwind readnone {
 ; X86-NEXT:  .LBB0_2:
 ; X86-NEXT:    retl
 ;
-; FASTISEL-X86-LABEL: smax_i8:
-; FASTISEL-X86:       # %bb.0:
-; FASTISEL-X86-NEXT:    movzbl {{[0-9]+}}(%esp), %ecx
-; FASTISEL-X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
-; FASTISEL-X86-NEXT:    cmpb %cl, %al
-; FASTISEL-X86-NEXT:    jg .LBB0_2
-; FASTISEL-X86-NEXT:  # %bb.1:
-; FASTISEL-X86-NEXT:    movl %ecx, %eax
-; FASTISEL-X86-NEXT:  .LBB0_2:
-; FASTISEL-X86-NEXT:    retl
+; GISEL-X86-LABEL: smax_i8:
+; GISEL-X86:       # %bb.0:
+; GISEL-X86-NEXT:    movzbl {{[0-9]+}}(%esp), %ecx
+; GISEL-X86-NEXT:    movzbl {{[0-9]+}}(%esp), %eax
+; GISEL-X86-NEXT:    xorl %edx, %edx
+; GISEL-X86-NEXT:    cmpb %al, %cl
+; GISEL-X86-NEXT:    setg %dl
+; GISEL-X86-NEXT:    andl $1, %edx
+; GISEL-X86-NEXT:    je .LBB0_2
+; GISEL-X86-NEXT:  # %bb.1:
+; GISEL-X86-NEXT:    movl %ecx, %eax
+; GISEL-X86-NEXT:  .LBB0_2:
+; GISEL-X86-NEXT:    # kill: def $al killed $al killed $eax
+; GISEL-X86-NEXT:    retl
     %ret = call i8 @llvm.smax.i8(i8 %a, i8 %b)
     ret i8 %ret
 }
@@ -57,25 +72,28 @@ define i16 @smax_i16(i16 %a, i16 %b) nounwind readnone {
 ; X64-NEXT:    # kill: def $ax killed $ax killed $eax
 ; X64-NEXT:    retq
 ;
-; FASTISEL-X64-LABEL: smax_i16:
-; FASTISEL-X64:       # %bb.0:
-; FASTISEL-X64-NEXT:    movl %esi, %eax
-; FASTISEL-X64-NEXT:    cmpw %ax, %di
-; FASTISEL-X64-NEXT:    cmovgl %edi, %eax
-; FASTISEL-X64-NEXT:    # kill: def $ax killed $ax killed $eax
-; FASTISEL-X64-NEXT:    retq
+; GISEL-X64-LABEL: smax_i16:
+; GISEL-X64:       # %bb.0:
+; GISEL-X64-NEXT:    movl %edi, %eax
+; GISEL-X64-NEXT:    xorl %ecx, %ecx
+; GISEL-X64-NEXT:    cmpw %si, %ax
+; GISEL-X64-NEXT:    setg %cl
+; GISEL-X64-NEXT:    andl $1, %ecx
+; GISEL-X64-NEXT:    cmovew %si, %ax
+; GISEL-X64-NEXT:    # kill: def $ax killed $ax killed $eax
+; GISEL-X64-NEXT:    retq
 ;
-; X86-LABEL: smax_i16:
-; X86:       # %bb.0:
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    cmpw %cx, %ax
-; X86-NEXT:    jg .LBB1_2
-; X86-NEXT:  # %bb.1:
-; X86-NEXT:    movl %ecx, %eax
-; X86-NEXT:  .LBB1_2:
-; X86-NEXT:    # kill: def $ax killed $ax killed $eax
-; X86-NEXT:    retl
+; DAG-X86-LABEL: smax_i16:
+; DAG-X86:       # %bb.0:
+; DAG-X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; DAG-X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; DAG-X86-NEXT:    cmpw %cx, %ax
+; DAG-X86-NEXT:    jg .LBB1_2
+; DAG-X86-NEXT:  # %bb.1:
+; DAG-X86-NEXT:    movl %ecx, %eax
+; DAG-X86-NEXT:  .LBB1_2:
+; DAG-X86-NEXT:    # kill: def $ax killed $ax killed $eax
+; DAG-X86-NEXT:    retl
 ;
 ; FASTISEL-X86-LABEL: smax_i16:
 ; FASTISEL-X86:       # %bb.0:
@@ -88,6 +106,21 @@ define i16 @smax_i16(i16 %a, i16 %b) nounwind readnone {
 ; FASTISEL-X86-NEXT:  .LBB1_2:
 ; FASTISEL-X86-NEXT:    # kill: def $ax killed $ax killed $eax
 ; FASTISEL-X86-NEXT:    retl
+;
+; GISEL-X86-LABEL: smax_i16:
+; GISEL-X86:       # %bb.0:
+; GISEL-X86-NEXT:    movzwl {{[0-9]+}}(%esp), %ecx
+; GISEL-X86-NEXT:    movzwl {{[0-9]+}}(%esp), %eax
+; GISEL-X86-NEXT:    xorl %edx, %edx
+; GISEL-X86-NEXT:    cmpw %ax, %cx
+; GISEL-X86-NEXT:    setg %dl
+; GISEL-X86-NEXT:    andl $1, %edx
+; GISEL-X86-NEXT:    je .LBB1_2
+; GISEL-X86-NEXT:  # %bb.1:
+; GISEL-X86-NEXT:    movl %ecx, %eax
+; GISEL-X86-NEXT:  .LBB1_2:
+; GISEL-X86-NEXT:    # kill: def $ax killed $ax killed $eax
+; GISEL-X86-NEXT:    retl
     %ret = call i16 @llvm.smax.i16(i16 %a, i16 %b)
     ret i16 %ret
 }
@@ -99,12 +132,15 @@ define i32 @smax_i32(i32 %a, i32 %b) nounwind readnone {
 ; X64-NEXT:    cmovgl %edi, %eax
 ; X64-NEXT:    retq
 ;
-; FASTISEL-X64-LABEL: smax_i32:
-; FASTISEL-X64:       # %bb.0:
-; FASTISEL-X64-NEXT:    movl %esi, %eax
-; FASTISEL-X64-NEXT:    cmpl %esi, %edi
-; FASTISEL-X64-NEXT:    cmovgl %edi, %eax
-; FASTISEL-X64-NEXT:    retq
+; GISEL-X64-LABEL: smax_i32:
+; GISEL-X64:       # %bb.0:
+; GISEL-X64-NEXT:    movl %edi, %eax
+; GISEL-X64-NEXT:    xorl %ecx, %ecx
+; GISEL-X64-NEXT:    cmpl %esi, %edi
+; GISEL-X64-NEXT:    setg %cl
+; GISEL-X64-NEXT:    andl $1, %ecx
+; GISEL-X64-NEXT:    cmovel %esi, %eax
+; GISEL-X64-NEXT:    retq
 ;
 ; X86-LABEL: smax_i32:
 ; X86:       # %bb.0:
@@ -117,16 +153,19 @@ define i32 @smax_i32(i32 %a, i32 %b) nounwind readnone {
 ; X86-NEXT:  .LBB2_2:
 ; X86-NEXT:    retl
 ;
-; FASTISEL-X86-LABEL: smax_i32:
-; FASTISEL-X86:       # %bb.0:
-; FASTISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
-; FASTISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; FASTISEL-X86-NEXT:    cmpl %ecx, %eax
-; FASTISEL-X86-NEXT:    jg .LBB2_2
-; FASTISEL-X86-NEXT:  # %bb.1:
-; FASTISEL-X86-NEXT:    movl %ecx, %eax
-; FASTISEL-X86-NEXT:  .LBB2_2:
-; FASTISEL-X86-NEXT:    retl
+; GISEL-X86-LABEL: smax_i32:
+; GISEL-X86:       # %bb.0:
+; GISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; GISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; GISEL-X86-NEXT:    xorl %edx, %edx
+; GISEL-X86-NEXT:    cmpl %eax, %ecx
+; GISEL-X86-NEXT:    setg %dl
+; GISEL-X86-NEXT:    andl $1, %edx
+; GISEL-X86-NEXT:    je .LBB2_2
+; GISEL-X86-NEXT:  # %bb.1:
+; GISEL-X86-NEXT:    movl %ecx, %eax
+; GISEL-X86-NEXT:  .LBB2_2:
+; GISEL-X86-NEXT:    retl
     %ret = call i32 @llvm.smax.i32(i32 %a, i32 %b)
     ret i32 %ret
 }
@@ -138,32 +177,35 @@ define i64 @smax_i64(i64 %a, i64 %b) nounwind readnone {
 ; X64-NEXT:    cmovgq %rdi, %rax
 ; X64-NEXT:    retq
 ;
-; FASTISEL-X64-LABEL: smax_i64:
-; FASTISEL-X64:       # %bb.0:
-; FASTISEL-X64-NEXT:    movq %rsi, %rax
-; FASTISEL-X64-NEXT:    cmpq %rsi, %rdi
-; FASTISEL-X64-NEXT:    cmovgq %rdi, %rax
-; FASTISEL-X64-NEXT:    retq
+; GISEL-X64-LABEL: smax_i64:
+; GISEL-X64:       # %bb.0:
+; GISEL-X64-NEXT:    movq %rdi, %rax
+; GISEL-X64-NEXT:    xorl %ecx, %ecx
+; GISEL-X64-NEXT:    cmpq %rsi, %rdi
+; GISEL-X64-NEXT:    setg %cl
+; GISEL-X64-NEXT:    andl $1, %ecx
+; GISEL-X64-NEXT:    cmoveq %rsi, %rax
+; GISEL-X64-NEXT:    retq
 ;
-; X86-LABEL: smax_i64:
-; X86:       # %bb.0:
-; X86-NEXT:    pushl %edi
-; X86-NEXT:    pushl %esi
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %edx
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
-; X86-NEXT:    movl {{[0-9]+}}(%esp), %esi
-; X86-NEXT:    cmpl %eax, %ecx
-; X86-NEXT:    movl %esi, %edi
-; X86-NEXT:    sbbl %edx, %edi
-; X86-NEXT:    jl .LBB3_2
-; X86-NEXT:  # %bb.1:
-; X86-NEXT:    movl %ecx, %eax
-; X86-NEXT:    movl %esi, %edx
-; X86-NEXT:  .LBB3_2:
-; X86-NEXT:    popl %esi
-; X86-NEXT:    popl %edi
-; X86-NEXT:    retl
+; DAG-X86-LABEL: smax_i64:
+; DAG-X86:       # %bb.0:
+; DAG-X86-NEXT:    pushl %edi
+; DAG-X86-NEXT:    pushl %esi
+; DAG-X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; DAG-X86-NEXT:    movl {{[0-9]+}}(%esp), %edx
+; DAG-X86-NEXT:    movl {{[0-9]+}}(%esp), %ecx
+; DAG-X86-NEXT:    movl {{[0-9]+}}(%esp), %esi
+; DAG-X86-NEXT:    cmpl %eax, %ecx
+; DAG-X86-NEXT:    movl %esi, %edi
+; DAG-X86-NEXT:    sbbl %edx, %edi
+; DAG-X86-NEXT:    jl .LBB3_2
+; DAG-X86-NEXT:  # %bb.1:
+; DAG-X86-NEXT:    movl %ecx, %eax
+; DAG-X86-NEXT:    movl %esi, %edx
+; DAG-X86-NEXT:  .LBB3_2:
+; DAG-X86-NEXT:    popl %esi
+; DAG-X86-NEXT:    popl %edi
+; DAG-X86-NEXT:    retl
 ;
 ; FASTISEL-X86-LABEL: smax_i64:
 ; FASTISEL-X86:       # %bb.0:
@@ -184,6 +226,44 @@ define i64 @smax_i64(i64 %a, i64 %b) nounwind readnone {
 ; FASTISEL-X86-NEXT:    popl %esi
 ; FASTISEL-X86-NEXT:    popl %edi
 ; FASTISEL-X86-NEXT:    retl
+;
+; GISEL-X86-LABEL: smax_i64:
+; GISEL-X86:       # %bb.0:
+; GISEL-X86-NEXT:    pushl %ebp
+; GISEL-X86-NEXT:    pushl %ebx
+; GISEL-X86-NEXT:    pushl %edi
+; GISEL-X86-NEXT:    pushl %esi
+; GISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %esi
+; GISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %ebp
+; GISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %eax
+; GISEL-X86-NEXT:    movl {{[0-9]+}}(%esp), %edx
+; GISEL-X86-NEXT:    cmpl %eax, %esi
+; GISEL-X86-NEXT:    seta %bl
+; GISEL-X86-NEXT:    xorl %ecx, %ecx
+; GISEL-X86-NEXT:    cmpl %edx, %ebp
+; GISEL-X86-NEXT:    setg %bh
+; GISEL-X86-NEXT:    sete %cl
+; GISEL-X86-NEXT:    testl %ecx, %ecx
+; GISEL-X86-NEXT:    je .LBB3_2
+; GISEL-X86-NEXT:  # %bb.1:
+; GISEL-X86-NEXT:    movb %bl, %bh
+; GISEL-X86-NEXT:  .LBB3_2:
+; GISEL-X86-NEXT:    movzbl %bh, %edi
+; GISEL-X86-NEXT:    andl $1, %edi
+; GISEL-X86-NEXT:    je .LBB3_4
+; GISEL-X86-NEXT:  # %bb.3:
+; GISEL-X86-NEXT:    movl %esi, %eax
+; GISEL-X86-NEXT:  .LBB3_4:
+; GISEL-X86-NEXT:    testl %edi, %edi
+; GISEL-X86-NEXT:    je .LBB3_6
+; GISEL-X86-NEXT:  # %bb.5:
+; GISEL-X86-NEXT:    movl %ebp, %edx
+; GISEL-X86-NEXT:  .LBB3_6:
+; GISEL-X86-NEXT:    popl %esi
+; GISEL-X86-NEXT:    popl %edi
+; GISEL-X86-NEXT:    popl %ebx
+; GISEL-X86-NEXT:    popl %ebp
+; GISEL-X86-NEXT:    retl
     %ret = call i64 @llvm.smax.i64(i64 %a, i64 %b)
     ret i64 %ret
 }