[llvm] [DAG] Add ISD::FP_TO_SINT_SAT/FP_TO_UINT_SAT handling to SelectionDAG::canCreateUndefOrPoison (PR #154244)

Ye Tian via llvm-commits llvm-commits at lists.llvm.org
Mon Aug 18 18:10:12 PDT 2025


https://github.com/TianYe717 created https://github.com/llvm/llvm-project/pull/154244

Related to [issue](https://github.com/llvm/llvm-project/issues/153366)

>From 63da7a24c5dea9a094229fccf3ced22fb6512fcd Mon Sep 17 00:00:00 2001
From: Ye Tian <939808194 at qq.com>
Date: Mon, 18 Aug 2025 17:31:06 +0800
Subject: [PATCH] [DAG] SelectionDAG::canCreateUndefOrPoison - add
 ISD::FP_TO_SINT_SAT/FP_TO_UINT_SAT handling + tests

---
 .../lib/CodeGen/SelectionDAG/SelectionDAG.cpp |  2 +
 .../test/CodeGen/X86/fptosi-sat-vector-128.ll | 46 +++++++++++++++++++
 .../test/CodeGen/X86/fptoui-sat-vector-128.ll | 37 +++++++++++++++
 3 files changed, 85 insertions(+)

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 84282d8a1c37b..f2cb0c600910e 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5748,6 +5748,8 @@ bool SelectionDAG::canCreateUndefOrPoison(SDValue Op, const APInt &DemandedElts,
   case ISD::FMA:
   case ISD::FMAD:
   case ISD::FP_EXTEND:
+  case ISD::FP_TO_SINT_SAT:
+  case ISD::FP_TO_UINT_SAT:
     // No poison except from flags (which is handled above)
     return false;
 
diff --git a/llvm/test/CodeGen/X86/fptosi-sat-vector-128.ll b/llvm/test/CodeGen/X86/fptosi-sat-vector-128.ll
index 7f6d64c21724a..a251e43e4295b 100644
--- a/llvm/test/CodeGen/X86/fptosi-sat-vector-128.ll
+++ b/llvm/test/CodeGen/X86/fptosi-sat-vector-128.ll
@@ -57,6 +57,52 @@ define <4 x i1> @test_signed_v4i1_v4f32(<4 x float> %f) nounwind {
   ret <4 x i1> %x
 }
 
+define <4 x i1> @test_freeze_signed_v4i1_v4f32(<4 x float> %f) nounwind {
+; CHECK-LABEL: test_freeze_signed_v4i1_v4f32:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    movaps %xmm0, %xmm1
+; CHECK-NEXT:    shufps {{.*#+}} xmm1 = xmm1[3,3],xmm0[3,3]
+; CHECK-NEXT:    movss {{.*#+}} xmm2 = [-1.0E+0,0.0E+0,0.0E+0,0.0E+0]
+; CHECK-NEXT:    xorl %eax, %eax
+; CHECK-NEXT:    ucomiss %xmm1, %xmm1
+; CHECK-NEXT:    maxss %xmm2, %xmm1
+; CHECK-NEXT:    xorps %xmm3, %xmm3
+; CHECK-NEXT:    minss %xmm3, %xmm1
+; CHECK-NEXT:    cvttss2si %xmm1, %ecx
+; CHECK-NEXT:    cmovpl %eax, %ecx
+; CHECK-NEXT:    movd %ecx, %xmm1
+; CHECK-NEXT:    movaps %xmm0, %xmm4
+; CHECK-NEXT:    unpckhpd {{.*#+}} xmm4 = xmm4[1],xmm0[1]
+; CHECK-NEXT:    ucomiss %xmm4, %xmm4
+; CHECK-NEXT:    maxss %xmm2, %xmm4
+; CHECK-NEXT:    minss %xmm3, %xmm4
+; CHECK-NEXT:    cvttss2si %xmm4, %ecx
+; CHECK-NEXT:    cmovpl %eax, %ecx
+; CHECK-NEXT:    movd %ecx, %xmm4
+; CHECK-NEXT:    punpckldq {{.*#+}} xmm4 = xmm4[0],xmm1[0],xmm4[1],xmm1[1]
+; CHECK-NEXT:    movaps %xmm0, %xmm1
+; CHECK-NEXT:    maxss %xmm2, %xmm1
+; CHECK-NEXT:    minss %xmm3, %xmm1
+; CHECK-NEXT:    cvttss2si %xmm1, %ecx
+; CHECK-NEXT:    ucomiss %xmm0, %xmm0
+; CHECK-NEXT:    cmovpl %eax, %ecx
+; CHECK-NEXT:    movd %ecx, %xmm1
+; CHECK-NEXT:    shufps {{.*#+}} xmm0 = xmm0[1,1,1,1]
+; CHECK-NEXT:    ucomiss %xmm0, %xmm0
+; CHECK-NEXT:    maxss %xmm2, %xmm0
+; CHECK-NEXT:    minss %xmm3, %xmm0
+; CHECK-NEXT:    cvttss2si %xmm0, %ecx
+; CHECK-NEXT:    cmovpl %eax, %ecx
+; CHECK-NEXT:    movd %ecx, %xmm0
+; CHECK-NEXT:    punpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
+; CHECK-NEXT:    punpcklqdq {{.*#+}} xmm1 = xmm1[0],xmm4[0]
+; CHECK-NEXT:    movdqa %xmm1, %xmm0
+; CHECK-NEXT:    retq
+  %x = call <4 x i1> @llvm.fptosi.sat.v4i1.v4f32(<4 x float> %f)
+  %y = freeze <4 x i1> %x
+  ret <4 x i1> %y
+}
+
 define <4 x i8> @test_signed_v4i8_v4f32(<4 x float> %f) nounwind {
 ; CHECK-LABEL: test_signed_v4i8_v4f32:
 ; CHECK:       # %bb.0:
diff --git a/llvm/test/CodeGen/X86/fptoui-sat-vector-128.ll b/llvm/test/CodeGen/X86/fptoui-sat-vector-128.ll
index ffbdd66529f5c..7b1db5c29abaf 100644
--- a/llvm/test/CodeGen/X86/fptoui-sat-vector-128.ll
+++ b/llvm/test/CodeGen/X86/fptoui-sat-vector-128.ll
@@ -48,6 +48,43 @@ define <4 x i1> @test_unsigned_v4i1_v4f32(<4 x float> %f) nounwind {
   ret <4 x i1> %x
 }
 
+define <4 x i1> @test_freeze_unsigned_v4i1_v4f32(<4 x float> %f) nounwind {
+; CHECK-LABEL: test_freeze_unsigned_v4i1_v4f32:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    movaps %xmm0, %xmm1
+; CHECK-NEXT:    shufps {{.*#+}} xmm1 = xmm1[3,3],xmm0[3,3]
+; CHECK-NEXT:    xorps %xmm2, %xmm2
+; CHECK-NEXT:    maxss %xmm2, %xmm1
+; CHECK-NEXT:    movss {{.*#+}} xmm3 = [1.0E+0,0.0E+0,0.0E+0,0.0E+0]
+; CHECK-NEXT:    minss %xmm3, %xmm1
+; CHECK-NEXT:    cvttss2si %xmm1, %eax
+; CHECK-NEXT:    movd %eax, %xmm1
+; CHECK-NEXT:    movaps %xmm0, %xmm4
+; CHECK-NEXT:    unpckhpd {{.*#+}} xmm4 = xmm4[1],xmm0[1]
+; CHECK-NEXT:    maxss %xmm2, %xmm4
+; CHECK-NEXT:    minss %xmm3, %xmm4
+; CHECK-NEXT:    cvttss2si %xmm4, %eax
+; CHECK-NEXT:    movd %eax, %xmm4
+; CHECK-NEXT:    punpckldq {{.*#+}} xmm4 = xmm4[0],xmm1[0],xmm4[1],xmm1[1]
+; CHECK-NEXT:    movaps %xmm0, %xmm1
+; CHECK-NEXT:    maxss %xmm2, %xmm1
+; CHECK-NEXT:    minss %xmm3, %xmm1
+; CHECK-NEXT:    cvttss2si %xmm1, %eax
+; CHECK-NEXT:    movd %eax, %xmm1
+; CHECK-NEXT:    shufps {{.*#+}} xmm0 = xmm0[1,1,1,1]
+; CHECK-NEXT:    maxss %xmm2, %xmm0
+; CHECK-NEXT:    minss %xmm3, %xmm0
+; CHECK-NEXT:    cvttss2si %xmm0, %eax
+; CHECK-NEXT:    movd %eax, %xmm0
+; CHECK-NEXT:    punpckldq {{.*#+}} xmm1 = xmm1[0],xmm0[0],xmm1[1],xmm0[1]
+; CHECK-NEXT:    punpcklqdq {{.*#+}} xmm1 = xmm1[0],xmm4[0]
+; CHECK-NEXT:    movdqa %xmm1, %xmm0
+; CHECK-NEXT:    retq
+  %x = call <4 x i1> @llvm.fptoui.sat.v4i1.v4f32(<4 x float> %f)
+  %y = freeze <4 x i1> %x
+  ret <4 x i1> %y
+}
+
 define <4 x i8> @test_unsigned_v4i8_v4f32(<4 x float> %f) nounwind {
 ; CHECK-LABEL: test_unsigned_v4i8_v4f32:
 ; CHECK:       # %bb.0:



More information about the llvm-commits mailing list