From 21de01f5554fa037f59b27525d2eb7342f5649c7 Mon Sep 17 00:00:00 2001
From: Haochen Jiang <haochen.jiang@intel.com>
Date: Wed, 9 Nov 2022 14:02:31 +0800
Subject: [PATCH] i386: Add ISA check for newly introduced prefetch builtins.

Hi all,

As Hongtao said, the fail on pentiumpro is caused by missing ISA check
since we are using emit_insn () through new builtins and it won't check
if the TARGET matches. Previously, the builtin in middle-end will check
that.

On pentiumpro, we won't have anything that supports any prefetch so that
it dropped into the pattern and then failed.

I have added the restrictions just like what middle-end builtin_prefetch
does. Also I added missing checks for PREFETCHI. Ok for trunk?

BRs,
Haochen

gcc/ChangeLog:

	* config/i386/i386-builtin.def (BDESC): Add
	OPTION_MASK_ISA2_PREFETCHI for prefetchi builtin.
	* config/i386/i386-expand.cc (ix86_expand_builtin):
	Add ISA check before emit_insn.
	* config/i386/prfchiintrin.h: Add target for intrin.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/prefetchi-5.c: New test.
---
 gcc/config/i386/i386-builtin.def            |  2 +-
 gcc/config/i386/i386-expand.cc              | 11 +++++++++--
 gcc/config/i386/prfchiintrin.h              | 14 +++++++++++++-
 gcc/testsuite/gcc.target/i386/prefetchi-5.c |  4 ++++
 4 files changed, 27 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/prefetchi-5.c

diff --git a/gcc/config/i386/i386-builtin.def b/gcc/config/i386/i386-builtin.def
index ea3aff7f125..5e0461acc00 100644
--- a/gcc/config/i386/i386-builtin.def
+++ b/gcc/config/i386/i386-builtin.def
@@ -498,7 +498,7 @@ BDESC (0, OPTION_MASK_ISA2_WIDEKL, CODE_FOR_nothing, "__builtin_ia32_aesencwide1
 BDESC (0, OPTION_MASK_ISA2_WIDEKL, CODE_FOR_nothing, "__builtin_ia32_aesencwide256kl_u8", IX86_BUILTIN_AESENCWIDE256KLU8, UNKNOWN, (int) UINT8_FTYPE_PV2DI_PCV2DI_PCVOID)
 
 /* PREFETCHI */
-BDESC (0, 0, CODE_FOR_prefetchi, "__builtin_ia32_prefetchi", IX86_BUILTIN_PREFETCHI, UNKNOWN, (int) VOID_FTYPE_PCVOID_INT)
+BDESC (0, OPTION_MASK_ISA2_PREFETCHI, CODE_FOR_prefetchi, "__builtin_ia32_prefetchi", IX86_BUILTIN_PREFETCHI, UNKNOWN, (int) VOID_FTYPE_PCVOID_INT)
 BDESC (0, 0, CODE_FOR_nothing, "__builtin_ia32_prefetch", IX86_BUILTIN_PREFETCH, UNKNOWN, (int) VOID_FTYPE_PCVOID_INT_INT_INT)
 
 BDESC_END (SPECIAL_ARGS, PURE_ARGS)
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index acf9e00d490..a166395db45 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -13133,7 +13133,7 @@ ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
 
 	if (INTVAL (op3) == 1)
 	  {
-	    if (TARGET_64BIT
+	    if (TARGET_64BIT && TARGET_PREFETCHI
 		&& local_func_symbolic_operand (op0, GET_MODE (op0)))
 	      emit_insn (gen_prefetchi (op0, op2));
 	    else
@@ -13152,7 +13152,14 @@ ix86_expand_builtin (tree exp, rtx target, rtx subtarget,
 		op0 = convert_memory_address (Pmode, op0);
 		op0 = copy_addr_to_reg (op0);
 	      }
-	    emit_insn (gen_prefetch (op0, op1, op2));
+
+	    if (TARGET_3DNOW || TARGET_PREFETCH_SSE
+		|| TARGET_PRFCHW || TARGET_PREFETCHWT1)
+	      emit_insn (gen_prefetch (op0, op1, op2));
+	    else if (!MEM_P (op0) && side_effects_p (op0))
+	      /* Don't do anything with direct references to volatile memory,
+		 but generate code to handle other side effects.  */
+	      emit_insn (op0);
 	  }
 
 	return 0;
diff --git a/gcc/config/i386/prfchiintrin.h b/gcc/config/i386/prfchiintrin.h
index 06deef488ba..996a4be1aba 100644
--- a/gcc/config/i386/prfchiintrin.h
+++ b/gcc/config/i386/prfchiintrin.h
@@ -30,6 +30,13 @@
 
 #ifdef __x86_64__
 
+
+#ifndef __PREFETCHI__
+#pragma GCC push_options
+#pragma GCC target("prefetchi")
+#define __DISABLE_PREFETCHI__
+#endif /* __PREFETCHI__ */
+
 extern __inline void
 __attribute__((__gnu_inline__, __always_inline__, __artificial__))
 _m_prefetchit0 (void* __P)
@@ -44,6 +51,11 @@ _m_prefetchit1 (void* __P)
   __builtin_ia32_prefetchi (__P, 2);
 }
 
-#endif
+#ifdef __DISABLE_PREFETCHI__
+#undef __DISABLE_PREFETCHI__
+#pragma GCC pop_options
+#endif /* __DISABLE_PREFETCHI__ */
+
+#endif /* __x86_64__ */
 
 #endif /* _PRFCHIINTRIN_H_INCLUDED */
diff --git a/gcc/testsuite/gcc.target/i386/prefetchi-5.c b/gcc/testsuite/gcc.target/i386/prefetchi-5.c
new file mode 100644
index 00000000000..8c26540f96a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/prefetchi-5.c
@@ -0,0 +1,4 @@
+/* { dg-do compile { target { ia32 } } } */
+/* { dg-options "-O0 -march=pentiumpro" } */
+
+#include "prefetchi-4.c"