From: Craig Topper <craig.topper@intel.com>
Date: Mon, 15 Apr 2019 21:06:32 +0000 (+0000)
Subject: [X86] Limit the 'x' inline assembly constraint to zmm0-15 when used for a 512 type.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=cc4577dd5da129570f9a8684cc84d00b15849d97;p=llvm

[X86] Limit the 'x' inline assembly constraint to zmm0-15 when used for a 512 type.

The 'v' constraint is used to select zmm0-31. This makes 512 bit consistent with 128/256-bit.a

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358450 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 514df8ccc09..6464b8ee065 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -43730,7 +43730,9 @@ X86TargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
       case MVT::v16f32:
       case MVT::v16i32:
       case MVT::v8i64:
-        return std::make_pair(0U, &X86::VR512RegClass);
+        if (VConstraint)
+          return std::make_pair(0U, &X86::VR512RegClass);
+        return std::make_pair(0U, &X86::VR512_0_15RegClass);
       }
       break;
     }
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 9f5f22b5610..7dec87cdcb0 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -163,6 +163,7 @@ X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
     case X86::RFP32RegClassID:
     case X86::RFP64RegClassID:
     case X86::RFP80RegClassID:
+    case X86::VR512_0_15RegClassID:
     case X86::VR512RegClassID:
       // Don't return a super-class that would shrink the spill size.
       // That can happen with the vector and float classes.
diff --git a/lib/Target/X86/X86RegisterInfo.td b/lib/Target/X86/X86RegisterInfo.td
index e03f0492cd7..c0acff9c8c3 100644
--- a/lib/Target/X86/X86RegisterInfo.td
+++ b/lib/Target/X86/X86RegisterInfo.td
@@ -570,6 +570,10 @@ def DFCCR : RegisterClass<"X86", [i32], 32, (add DF)> {
 def VR512 : RegisterClass<"X86", [v16f32, v8f64, v64i8, v32i16, v16i32, v8i64],
                           512, (sequence "ZMM%u", 0, 31)>;
 
+// Represents the lower 16 registers that have VEX/legacy encodable subregs.
+def VR512_0_15 : RegisterClass<"X86", [v16f32, v8f64, v64i8, v32i16, v16i32, v8i64],
+                               512, (sequence "ZMM%u", 0, 15)>;
+
 // Scalar AVX-512 floating point registers.
 def FR32X : RegisterClass<"X86", [f32], 32, (sequence "XMM%u", 0, 31)>;
 
diff --git a/test/CodeGen/X86/inline-asm-avx512f-x-constraint.ll b/test/CodeGen/X86/inline-asm-avx512f-x-constraint.ll
new file mode 100644
index 00000000000..2f711a86bc2
--- /dev/null
+++ b/test/CodeGen/X86/inline-asm-avx512f-x-constraint.ll
@@ -0,0 +1,10 @@
+; RUN: llc < %s -mtriple=x86_64-unknown-unknown -mattr=avx512f -stop-after=expand-isel-pseudos | FileCheck %s
+
+; CHECK: %[[REG1:.*]]:vr512_0_15 = COPY %1
+; CHECK: %[[REG2:.*]]:vr512_0_15 = COPY %2
+; CHECK: INLINEASM &"vpaddq\09$3, $2, $0 {$1}", 0, 7340042, def %{{.*}}, 1179657, %{{.*}}, 7340041, %[[REG1]], 7340041, %[[REG2]], 12, implicit-def early-clobber $df, 12, implicit-def early-clobber $fpsw, 12, implicit-def early-clobber $eflags
+define <8 x i64> @mask_Yk_i8(i8 signext %msk, <8 x i64> %x, <8 x i64> %y) {
+entry:
+  %0 = tail call <8 x i64> asm "vpaddq\09$3, $2, $0 {$1}", "=x,^Yk,x,x,~{dirflag},~{fpsr},~{flags}"(i8 %msk, <8 x i64> %x, <8 x i64> %y)
+  ret <8 x i64> %0
+}