From d3e140ac549a2117e82dac51f2e739b20f9c7941 Mon Sep 17 00:00:00 2001
From: liuhongt <hongtao.liu@intel.com>
Date: Thu, 7 Dec 2023 09:17:27 +0800
Subject: [PATCH] Don't assume it's AVX_U128_CLEAN after call_insn whose
abi.mode_clobber(V4DImode) deosn't contains all SSE_REGS.
If the function desn't clobber any sse registers or only clobber
128-bit part, then vzeroupper isn't issued before the function exit.
the status not CLEAN but ANY after the function.
Also for sibling_call, it's safe to issue an vzeroupper. Also there
could be missing vzeroupper since there's no mode_exit for
sibling_call_p.
gcc/ChangeLog:
PR target/112891
* config/i386/i386.cc (ix86_avx_u128_mode_after): Return
AVX_U128_ANY if callee_abi doesn't clobber all_sse_regs to
align with ix86_avx_u128_mode_needed.
(ix86_avx_u128_mode_needed): Return AVX_U128_ClEAN for
sibling_call.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr112891.c: New test.
* gcc.target/i386/pr112891-2.c: New test.
---
gcc/config/i386/i386.cc | 22 +++++++++++++---
gcc/testsuite/gcc.target/i386/pr112891-2.c | 30 ++++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr112891.c | 29 +++++++++++++++++++++
3 files changed, 78 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr112891-2.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr112891.c
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 25fb5703ab03..56cc15de93df 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -14488,8 +14488,12 @@ ix86_avx_u128_mode_needed (rtx_insn *insn)
modes wider than 256 bits. It's only safe to issue a
vzeroupper if all SSE registers are clobbered. */
const function_abi &abi = insn_callee_abi (insn);
- if (!hard_reg_set_subset_p (reg_class_contents[SSE_REGS],
- abi.mode_clobbers (V4DImode)))
+ /* Should be safe to issue an vzeroupper before sibling_call_p.
+ Also there not mode_exit for sibling_call, so there could be
+ missing vzeroupper for that. */
+ if (!(SIBLING_CALL_P (insn)
+ || hard_reg_set_subset_p (reg_class_contents[SSE_REGS],
+ abi.mode_clobbers (V4DImode))))
return AVX_U128_ANY;
return AVX_U128_CLEAN;
@@ -14627,7 +14631,19 @@ ix86_avx_u128_mode_after (int mode, rtx_insn *insn)
bool avx_upper_reg_found = false;
note_stores (insn, ix86_check_avx_upper_stores, &avx_upper_reg_found);
- return avx_upper_reg_found ? AVX_U128_DIRTY : AVX_U128_CLEAN;
+ if (avx_upper_reg_found)
+ return AVX_U128_DIRTY;
+
+ /* If the function desn't clobber any sse registers or only clobber
+ 128-bit part, Then vzeroupper isn't issued before the function exit.
+ the status not CLEAN but ANY after the function. */
+ const function_abi &abi = insn_callee_abi (insn);
+ if (!(SIBLING_CALL_P (insn)
+ || hard_reg_set_subset_p (reg_class_contents[SSE_REGS],
+ abi.mode_clobbers (V4DImode))))
+ return AVX_U128_ANY;
+
+ return AVX_U128_CLEAN;
}
/* Otherwise, return current mode. Remember that if insn
diff --git a/gcc/testsuite/gcc.target/i386/pr112891-2.c b/gcc/testsuite/gcc.target/i386/pr112891-2.c
new file mode 100644
index 000000000000..164c3985d508
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr112891-2.c
@@ -0,0 +1,30 @@
+/* { dg-do compile } */
+/* { dg-options "-mavx2 -O3" } */
+/* { dg-final { scan-assembler-times "vzeroupper" 1 } } */
+
+void
+__attribute__((noinline))
+bar (double* a)
+{
+ a[0] = 1.0;
+ a[1] = 2.0;
+}
+
+double
+__attribute__((noinline))
+foo (double* __restrict a, double* b)
+{
+ a[0] += b[0];
+ a[1] += b[1];
+ a[2] += b[2];
+ a[3] += b[3];
+ bar (b);
+ return a[5] + b[5];
+}
+
+double
+foo1 (double* __restrict a, double* b)
+{
+ double c = foo (a, b);
+ return __builtin_exp (c);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr112891.c b/gcc/testsuite/gcc.target/i386/pr112891.c
new file mode 100644
index 000000000000..dbf6c67948a4
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr112891.c
@@ -0,0 +1,29 @@
+/* { dg-do compile } */
+/* { dg-options "-mavx2 -O3" } */
+/* { dg-final { scan-assembler-times "vzeroupper" 1 } } */
+
+void
+__attribute__((noinline))
+bar (double* a)
+{
+ a[0] = 1.0;
+ a[1] = 2.0;
+}
+
+void
+__attribute__((noinline))
+foo (double* __restrict a, double* b)
+{
+ a[0] += b[0];
+ a[1] += b[1];
+ a[2] += b[2];
+ a[3] += b[3];
+ bar (b);
+}
+
+double
+foo1 (double* __restrict a, double* b)
+{
+ foo (a, b);
+ return __builtin_exp (b[1]);
+}
--
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