diff mbox series

[04/16,APX,NDD] Disable seg_prefixed memory usage for NDD add

Message ID 20231115094705.3976553-5-hongyu.wang@intel.com
State New
Headers show
Series Support Intel APX NDD | expand

Commit Message

Hongyu Wang Nov. 15, 2023, 9:46 a.m. UTC 
NDD uses evex prefix, so when segment prefix is also applied, the instruction
could excceed its 15byte limit, especially adding immediates. This could happen
when "e" constraint accepts any UNSPEC_TPOFF/UNSPEC_NTPOFF constant and it will
add the offset to segment register, which will be encoded using segment prefix.
Disable those *POFF constant usage in NDD add alternatives with new constraint.

gcc/ChangeLog:

	* config/i386/constraints.md (je): New constraint.
	* config/i386/i386-protos.h (x86_no_poff_operand_p): New function to
	check any *POFF constant.
	* config/i386/i386.cc (x86_no_poff_operand_p): New prototype.
	* config/i386/i386.md (*add<mode>_1): Split out je alternative for add.
---
 gcc/config/i386/constraints.md |  5 +++++
 gcc/config/i386/i386-protos.h  |  1 +
 gcc/config/i386/i386.cc        | 25 +++++++++++++++++++++++++
 gcc/config/i386/i386.md        | 10 +++++-----
 4 files changed, 36 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md
index cbee31fa40a..c6b51324294 100644
--- a/gcc/config/i386/constraints.md
+++ b/gcc/config/i386/constraints.md
@@ -433,3 +433,8 @@  (define_address_constraint "jb"
 
 (define_register_constraint  "jc"
  "TARGET_APX_EGPR && !TARGET_AVX ? GENERAL_GPR16 : GENERAL_REGS")
+
+(define_constraint  "je"
+  "@internal constant that do not allow any unspec global offsets"
+  (and (match_operand 0 "x86_64_immediate_operand")
+       (match_test "x86_no_poff_operand_p (op)")))
diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
index 3e08eae4e79..5d902e2925b 100644
--- a/gcc/config/i386/i386-protos.h
+++ b/gcc/config/i386/i386-protos.h
@@ -66,6 +66,7 @@  extern bool x86_extended_QIreg_mentioned_p (rtx_insn *);
 extern bool x86_extended_reg_mentioned_p (rtx);
 extern bool x86_extended_rex2reg_mentioned_p (rtx);
 extern bool x86_evex_reg_mentioned_p (rtx [], int);
+extern bool x86_no_poff_operand_p (rtx);
 extern bool x86_maybe_negate_const_int (rtx *, machine_mode);
 extern machine_mode ix86_cc_mode (enum rtx_code, rtx, rtx);
 
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 3779d5b1206..47159b06f7d 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -23292,6 +23292,31 @@  x86_evex_reg_mentioned_p (rtx operands[], int nops)
   return false;
 }
 
+/* Return true when rtx operand does not contain any UNSPEC_*POFF related
+   constant to avoid APX_NDD instructions excceed encoding length limit.  */
+bool
+x86_no_poff_operand_p (rtx operand)
+{
+  if (GET_CODE (operand) == CONST)
+    {
+      rtx op = XEXP (operand, 0);
+      if (GET_CODE (op) == PLUS)
+	op = XEXP (op, 0);
+	
+      if (GET_CODE (op) == UNSPEC)
+	{
+	  int unspec = XINT (op, 1);
+	  return (unspec != UNSPEC_NTPOFF
+		  && unspec != UNSPEC_TPOFF
+		  && unspec != UNSPEC_DTPOFF
+		  && unspec != UNSPEC_GOTTPOFF
+		  && unspec != UNSPEC_GOTNTPOFF
+		  && unspec != UNSPEC_INDNTPOFF);
+	}
+    }
+  return true;
+}
+
 /* If profitable, negate (without causing overflow) integer constant
    of mode MODE at location LOC.  Return true in this case.  */
 bool
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 7ddb2cb2a71..ecd06625a7d 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -6359,15 +6359,15 @@  (define_insn_and_split "*add<dwi>3_doubleword_concat_zext"
  "split_double_mode (<DWI>mode, &operands[0], 1, &operands[0], &operands[5]);")
 
 (define_insn "*add<mode>_1"
-  [(set (match_operand:SWI48 0 "nonimmediate_operand" "=rm,r,r,r,r,r")
+  [(set (match_operand:SWI48 0 "nonimmediate_operand" "=rm,r,r,r,r,r,r,r")
 	(plus:SWI48
-	  (match_operand:SWI48 1 "nonimmediate_operand" "%0,0,r,r,rm,r")
-	  (match_operand:SWI48 2 "x86_64_general_operand" "re,BM,0,le,re,BM")))
+	  (match_operand:SWI48 1 "nonimmediate_operand" "%0,0,r,r,rm,r,m,r")
+	  (match_operand:SWI48 2 "x86_64_general_operand" "re,BM,0,le,r,e,je,BM")))
    (clobber (reg:CC FLAGS_REG))]
   "ix86_binary_operator_ok (PLUS, <MODE>mode, operands,
 			    ix86_can_use_ndd_p (PLUS))"
 {
-  bool use_ndd = (which_alternative == 4 || which_alternative == 5);
+  bool use_ndd = (which_alternative >= 4);
   switch (get_attr_type (insn))
     {
     case TYPE_LEA:
@@ -6398,7 +6398,7 @@  (define_insn "*add<mode>_1"
 		    : "add{<imodesuffix>}\t{%2, %0|%0, %2}";
     }
 }
-  [(set_attr "isa" "*,*,*,*,apx_ndd,apx_ndd")
+  [(set_attr "isa" "*,*,*,*,apx_ndd,apx_ndd,apx_ndd,apx_ndd")
    (set (attr "type")
      (cond [(eq_attr "alternative" "3")
               (const_string "lea")