[llvm] r327799 - [InstCombine] peek through unsigned FP casts for zero-equality compares (PR36682)
Roman Lebedev via llvm-commits
llvm-commits at lists.llvm.org
Sun Mar 18 08:53:02 PDT 2018
Author: lebedevri
Date: Sun Mar 18 08:53:02 2018
New Revision: 327799
URL: http://llvm.org/viewvc/llvm-project?rev=327799&view=rev
Log:
[InstCombine] peek through unsigned FP casts for zero-equality compares (PR36682)
Summary:
This pattern came up in PR36682 / D44390
https://bugs.llvm.org/show_bug.cgi?id=36682
https://reviews.llvm.org/D44390
https://godbolt.org/g/oKvT5H
See also D44416
Reviewers: spatel, majnemer, efriedma, arsenm
Reviewed By: spatel
Subscribers: wdng, llvm-commits
Differential Revision: https://reviews.llvm.org/D44424
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
llvm/trunk/test/Transforms/InstCombine/cast-unsigned-icmp-eqcmp-0.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=327799&r1=327798&r2=327799&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Sun Mar 18 08:53:02 2018
@@ -4506,6 +4506,15 @@ Instruction *InstCombiner::visitICmpInst
return New;
}
+ Value *X;
+
+ // Zero-equality checks are preserved through unsigned floating-point casts:
+ // icmp eq (bitcast (uitofp X)), 0 --> icmp eq X, 0
+ // icmp ne (bitcast (uitofp X)), 0 --> icmp ne X, 0
+ if (match(Op0, m_BitCast(m_UIToFP(m_Value(X)))))
+ if (I.isEquality() && match(Op1, m_Zero()))
+ return new ICmpInst(Pred, X, ConstantInt::getNullValue(X->getType()));
+
// Test to see if the operands of the icmp are casted versions of other
// values. If the ptr->ptr cast can be stripped off both arguments, we do so
// now.
Modified: llvm/trunk/test/Transforms/InstCombine/cast-unsigned-icmp-eqcmp-0.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/cast-unsigned-icmp-eqcmp-0.ll?rev=327799&r1=327798&r2=327799&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/cast-unsigned-icmp-eqcmp-0.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/cast-unsigned-icmp-eqcmp-0.ll Sun Mar 18 08:53:02 2018
@@ -1,18 +1,16 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -instcombine -S | FileCheck %s
-; target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
-
; This is related to https://bugs.llvm.org/show_bug.cgi?id=36682
; FIXME: *all* of these are true tests.
; In *all* of these, uitofp and bitcast should be instcombine'd out.
+; FIXME: icmp eq/ne does not ignore undef elements in vectors.
+
define i1 @i32_cast_cmp_eq_int_0_uitofp_float(i32 %i) {
; CHECK-LABEL: @i32_cast_cmp_eq_int_0_uitofp_float(
-; CHECK-NEXT: [[F:%.*]] = uitofp i32 [[I:%.*]] to float
-; CHECK-NEXT: [[B:%.*]] = bitcast float [[F]] to i32
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[B]], 0
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[I:%.*]], 0
; CHECK-NEXT: ret i1 [[CMP]]
;
%f = uitofp i32 %i to float
@@ -23,9 +21,7 @@ define i1 @i32_cast_cmp_eq_int_0_uitofp_
define <2 x i1> @i32_cast_cmp_eq_int_0_uitofp_float_vec(<2 x i32> %i) {
; CHECK-LABEL: @i32_cast_cmp_eq_int_0_uitofp_float_vec(
-; CHECK-NEXT: [[F:%.*]] = uitofp <2 x i32> [[I:%.*]] to <2 x float>
-; CHECK-NEXT: [[B:%.*]] = bitcast <2 x float> [[F]] to <2 x i32>
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i32> [[B]], zeroinitializer
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i32> [[I:%.*]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%f = uitofp <2 x i32> %i to <2 x float>
@@ -49,9 +45,7 @@ define <3 x i1> @i32_cast_cmp_eq_int_0_u
define i1 @i32_cast_cmp_ne_int_0_uitofp_float(i32 %i) {
; CHECK-LABEL: @i32_cast_cmp_ne_int_0_uitofp_float(
-; CHECK-NEXT: [[F:%.*]] = uitofp i32 [[I:%.*]] to float
-; CHECK-NEXT: [[B:%.*]] = bitcast float [[F]] to i32
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[B]], 0
+; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[I:%.*]], 0
; CHECK-NEXT: ret i1 [[CMP]]
;
%f = uitofp i32 %i to float
@@ -62,9 +56,7 @@ define i1 @i32_cast_cmp_ne_int_0_uitofp_
define <2 x i1> @i32_cast_cmp_ne_int_0_uitofp_float_vec(<2 x i32> %i) {
; CHECK-LABEL: @i32_cast_cmp_ne_int_0_uitofp_float_vec(
-; CHECK-NEXT: [[F:%.*]] = uitofp <2 x i32> [[I:%.*]] to <2 x float>
-; CHECK-NEXT: [[B:%.*]] = bitcast <2 x float> [[F]] to <2 x i32>
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i32> [[B]], zeroinitializer
+; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i32> [[I:%.*]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%f = uitofp <2 x i32> %i to <2 x float>
@@ -88,9 +80,7 @@ define <3 x i1> @i32_cast_cmp_ne_int_0_u
define i1 @i32_cast_cmp_eq_int_0_uitofp_double(i32 %i) {
; CHECK-LABEL: @i32_cast_cmp_eq_int_0_uitofp_double(
-; CHECK-NEXT: [[F:%.*]] = uitofp i32 [[I:%.*]] to double
-; CHECK-NEXT: [[B:%.*]] = bitcast double [[F]] to i64
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[B]], 0
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[I:%.*]], 0
; CHECK-NEXT: ret i1 [[CMP]]
;
%f = uitofp i32 %i to double
@@ -101,9 +91,7 @@ define i1 @i32_cast_cmp_eq_int_0_uitofp_
define <2 x i1> @i32_cast_cmp_eq_int_0_uitofp_double_vec(<2 x i32> %i) {
; CHECK-LABEL: @i32_cast_cmp_eq_int_0_uitofp_double_vec(
-; CHECK-NEXT: [[F:%.*]] = uitofp <2 x i32> [[I:%.*]] to <2 x double>
-; CHECK-NEXT: [[B:%.*]] = bitcast <2 x double> [[F]] to <2 x i64>
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i64> [[B]], zeroinitializer
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i32> [[I:%.*]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%f = uitofp <2 x i32> %i to <2 x double>
@@ -127,9 +115,7 @@ define <3 x i1> @i32_cast_cmp_eq_int_0_u
define i1 @i32_cast_cmp_ne_int_0_uitofp_double(i32 %i) {
; CHECK-LABEL: @i32_cast_cmp_ne_int_0_uitofp_double(
-; CHECK-NEXT: [[F:%.*]] = uitofp i32 [[I:%.*]] to double
-; CHECK-NEXT: [[B:%.*]] = bitcast double [[F]] to i64
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne i64 [[B]], 0
+; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[I:%.*]], 0
; CHECK-NEXT: ret i1 [[CMP]]
;
%f = uitofp i32 %i to double
@@ -140,9 +126,7 @@ define i1 @i32_cast_cmp_ne_int_0_uitofp_
define <2 x i1> @i32_cast_cmp_ne_int_0_uitofp_double_vec(<2 x i32> %i) {
; CHECK-LABEL: @i32_cast_cmp_ne_int_0_uitofp_double_vec(
-; CHECK-NEXT: [[F:%.*]] = uitofp <2 x i32> [[I:%.*]] to <2 x double>
-; CHECK-NEXT: [[B:%.*]] = bitcast <2 x double> [[F]] to <2 x i64>
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i64> [[B]], zeroinitializer
+; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i32> [[I:%.*]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%f = uitofp <2 x i32> %i to <2 x double>
@@ -166,9 +150,7 @@ define <3 x i1> @i32_cast_cmp_ne_int_0_u
define i1 @i32_cast_cmp_eq_int_0_uitofp_half(i32 %i) {
; CHECK-LABEL: @i32_cast_cmp_eq_int_0_uitofp_half(
-; CHECK-NEXT: [[F:%.*]] = uitofp i32 [[I:%.*]] to half
-; CHECK-NEXT: [[B:%.*]] = bitcast half [[F]] to i16
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq i16 [[B]], 0
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[I:%.*]], 0
; CHECK-NEXT: ret i1 [[CMP]]
;
%f = uitofp i32 %i to half
@@ -179,9 +161,7 @@ define i1 @i32_cast_cmp_eq_int_0_uitofp_
define <2 x i1> @i32_cast_cmp_eq_int_0_uitofp_half_vec(<2 x i32> %i) {
; CHECK-LABEL: @i32_cast_cmp_eq_int_0_uitofp_half_vec(
-; CHECK-NEXT: [[F:%.*]] = uitofp <2 x i32> [[I:%.*]] to <2 x half>
-; CHECK-NEXT: [[B:%.*]] = bitcast <2 x half> [[F]] to <2 x i16>
-; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i16> [[B]], zeroinitializer
+; CHECK-NEXT: [[CMP:%.*]] = icmp eq <2 x i32> [[I:%.*]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%f = uitofp <2 x i32> %i to <2 x half>
@@ -205,9 +185,7 @@ define <3 x i1> @i32_cast_cmp_eq_int_0_u
define i1 @i32_cast_cmp_ne_int_0_uitofp_half(i32 %i) {
; CHECK-LABEL: @i32_cast_cmp_ne_int_0_uitofp_half(
-; CHECK-NEXT: [[F:%.*]] = uitofp i32 [[I:%.*]] to half
-; CHECK-NEXT: [[B:%.*]] = bitcast half [[F]] to i16
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne i16 [[B]], 0
+; CHECK-NEXT: [[CMP:%.*]] = icmp ne i32 [[I:%.*]], 0
; CHECK-NEXT: ret i1 [[CMP]]
;
%f = uitofp i32 %i to half
@@ -218,9 +196,7 @@ define i1 @i32_cast_cmp_ne_int_0_uitofp_
define <2 x i1> @i32_cast_cmp_ne_int_0_uitofp_half_vec(<2 x i32> %i) {
; CHECK-LABEL: @i32_cast_cmp_ne_int_0_uitofp_half_vec(
-; CHECK-NEXT: [[F:%.*]] = uitofp <2 x i32> [[I:%.*]] to <2 x half>
-; CHECK-NEXT: [[B:%.*]] = bitcast <2 x half> [[F]] to <2 x i16>
-; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i16> [[B]], zeroinitializer
+; CHECK-NEXT: [[CMP:%.*]] = icmp ne <2 x i32> [[I:%.*]], zeroinitializer
; CHECK-NEXT: ret <2 x i1> [[CMP]]
;
%f = uitofp <2 x i32> %i to <2 x half>
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