Commit eb15d001 authored by Thomas Lively's avatar Thomas Lively
Browse files

[WebAssembly] Lower away condition truncations for scalar selects 

Reviewers: aheejin, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D53676

llvm-svn: 345521
parent 3a2f3c2c

llvm/lib/Target/WebAssembly/WebAssemblyInstrFloat.td

+7 −0
Original line number Diff line number Diff line
@@ -122,3 +122,10 @@ def : Pat<(select (i32 (seteq I32:$cond, 0)), F32:$lhs, F32:$rhs), 
          (SELECT_F32 F32:$rhs, F32:$lhs, I32:$cond)>;

def : Pat<(select (i32 (seteq I32:$cond, 0)), F64:$lhs, F64:$rhs),

          (SELECT_F64 F64:$rhs, F64:$lhs, I32:$cond)>;



// The legalizer inserts an unnecessary `and 1` to make input conform

// to getBooleanContents, which we can lower away.

def : Pat<(select (i32 (and I32:$cond, 1)), F32:$lhs, F32:$rhs),

          (SELECT_F32 F32:$lhs, F32:$rhs, I32:$cond)>;

def : Pat<(select (i32 (and I32:$cond, 1)), F64:$lhs, F64:$rhs),

          (SELECT_F64 F64:$lhs, F64:$rhs, I32:$cond)>;

llvm/lib/Target/WebAssembly/WebAssemblyInstrInteger.td

+7 −0
Original line number Diff line number Diff line
@@ -122,3 +122,10 @@ def : Pat<(select (i32 (seteq I32:$cond, 0)), I32:$lhs, I32:$rhs), 
          (SELECT_I32 I32:$rhs, I32:$lhs, I32:$cond)>;

def : Pat<(select (i32 (seteq I32:$cond, 0)), I64:$lhs, I64:$rhs),

          (SELECT_I64 I64:$rhs, I64:$lhs, I32:$cond)>;



// The legalizer inserts an unnecessary `and 1` to make input conform

// to getBooleanContents, which we can lower away.

def : Pat<(select (i32 (and I32:$cond, 1)), I32:$lhs, I32:$rhs),

          (SELECT_I32 I32:$lhs, I32:$rhs, I32:$cond)>;

def : Pat<(select (i32 (and I32:$cond, 1)), I64:$lhs, I64:$rhs),

          (SELECT_I64 I64:$lhs, I64:$rhs, I32:$cond)>;

llvm/test/CodeGen/WebAssembly/select.ll

+41 −1
Original line number Diff line number Diff line 
; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers | FileCheck %s

; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers | FileCheck %s --check-prefixes CHECK,SLOW

; RUN: llc < %s -asm-verbose=false -disable-wasm-fallthrough-return-opt -wasm-disable-explicit-locals -wasm-keep-registers -fast-isel -fast-isel-abort=1 | FileCheck %s



; Test that wasm select instruction is selected from LLVM select instruction.
@@ -16,6 +16,16 @@ define i32 @select_i32_bool(i1 zeroext %a, i32 %b, i32 %c) { 
  ret i32 %cond

}



; CHECK-LABEL: select_i32_bool_nozext:

; CHECK-NEXT: .param     i32, i32, i32{{$}}

; CHECK-NEXT: .result    i32{{$}}

; SLOW-NEXT: i32.select $push0=, $1, $2, $0{{$}}

; SLOW-NEXT: return     $pop0{{$}}

define i32 @select_i32_bool_nozext(i1 %a, i32 %b, i32 %c) {

  %cond = select i1 %a, i32 %b, i32 %c

  ret i32 %cond

}



; CHECK-LABEL: select_i32_eq:

; CHECK-NEXT: .param     i32, i32, i32{{$}}

; CHECK-NEXT: .result    i32{{$}}
@@ -48,6 +58,16 @@ define i64 @select_i64_bool(i1 zeroext %a, i64 %b, i64 %c) { 
  ret i64 %cond

}



; CHECK-LABEL: select_i64_bool_nozext:

; CHECK-NEXT: .param     i32, i64, i64{{$}}

; CHECK-NEXT: .result    i64{{$}}

; SLOW-NEXT: i64.select $push0=, $1, $2, $0{{$}}

; SLOW-NEXT: return     $pop0{{$}}

define i64 @select_i64_bool_nozext(i1 %a, i64 %b, i64 %c) {

  %cond = select i1 %a, i64 %b, i64 %c

  ret i64 %cond

}



; CHECK-LABEL: select_i64_eq:

; CHECK-NEXT: .param     i32, i64, i64{{$}}

; CHECK-NEXT: .result    i64{{$}}
@@ -80,6 +100,16 @@ define float @select_f32_bool(i1 zeroext %a, float %b, float %c) { 
  ret float %cond

}



; CHECK-LABEL: select_f32_bool_nozext:

; CHECK-NEXT: .param     i32, f32, f32{{$}}

; CHECK-NEXT: .result    f32{{$}}

; SLOW-NEXT: f32.select $push0=, $1, $2, $0{{$}}

; SLOW-NEXT: return     $pop0{{$}}

define float @select_f32_bool_nozext(i1 %a, float %b, float %c) {

  %cond = select i1 %a, float %b, float %c

  ret float %cond

}



; CHECK-LABEL: select_f32_eq:

; CHECK-NEXT: .param     i32, f32, f32{{$}}

; CHECK-NEXT: .result    f32{{$}}
@@ -112,6 +142,16 @@ define double @select_f64_bool(i1 zeroext %a, double %b, double %c) { 
  ret double %cond

}



; CHECK-LABEL: select_f64_bool_nozext:

; CHECK-NEXT: .param     i32, f64, f64{{$}}

; CHECK-NEXT: .result    f64{{$}}

; SLOW-NEXT: f64.select $push0=, $1, $2, $0{{$}}

; SLOW-NEXT: return     $pop0{{$}}

define double @select_f64_bool_nozext(i1 %a, double %b, double %c) {

  %cond = select i1 %a, double %b, double %c

  ret double %cond

}



; CHECK-LABEL: select_f64_eq:

; CHECK-NEXT: .param     i32, f64, f64{{$}}

; CHECK-NEXT: .result    f64{{$}}