From: Chenghui Pan <panchenghui@loongson.cn>
Date: Thu, 14 Mar 2024 01:26:54 +0000 (+0800)
Subject: LoongArch: Remove masking process for operand 3 of xvpermi.q.
X-Git-Tag: basepoints/gcc-15~653
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d7d05824ae68da24908d97a10b9ec59d08f75a90;p=thirdparty%2Fgcc.git

LoongArch: Remove masking process for operand 3 of xvpermi.q.

The behavior of non-zero unused bits in xvpermi.q instruction's
third operand is undefined on LoongArch, according to our
discussion (https://github.com/llvm/llvm-project/pull/83540),
we think that keeping original insn operand as unmodified
state is better solution.

This patch partially reverts 7b158e036a95b1ab40793dd53bed7dbd770ffdaf.

gcc/ChangeLog:

	* config/loongarch/lasx.md (lasx_xvpermi_q_<LASX:mode>):
	Remove masking of operand 3.

gcc/testsuite/ChangeLog:

	* gcc.target/loongarch/vector/lasx/lasx-xvpermi_q.c:
	Reposition operand 3's value into instruction's defined accept range.
---

diff --git a/gcc/config/loongarch/lasx.md b/gcc/config/loongarch/lasx.md
index ac84db7f0ce1..3f25c0c17563 100644
--- a/gcc/config/loongarch/lasx.md
+++ b/gcc/config/loongarch/lasx.md
@@ -640,8 +640,6 @@
    (set_attr "mode" "<MODE>")])
 
 ;; xvpermi.q
-;; Unused bits in operands[3] need be set to 0 to avoid
-;; causing undefined behavior on LA464.
 (define_insn "lasx_xvpermi_q_<LASX:mode>"
   [(set (match_operand:LASX 0 "register_operand" "=f")
 	(unspec:LASX
@@ -651,9 +649,6 @@
 	  UNSPEC_LASX_XVPERMI_Q))]
   "ISA_HAS_LASX"
 {
-  int mask = 0x33;
-  mask &= INTVAL (operands[3]);
-  operands[3] = GEN_INT (mask);
   return "xvpermi.q\t%u0,%u2,%3";
 }
   [(set_attr "type" "simd_splat")
diff --git a/gcc/testsuite/gcc.target/loongarch/vector/lasx/lasx-xvpermi_q.c b/gcc/testsuite/gcc.target/loongarch/vector/lasx/lasx-xvpermi_q.c
index dbc29d2fb22c..f89dfc311207 100644
--- a/gcc/testsuite/gcc.target/loongarch/vector/lasx/lasx-xvpermi_q.c
+++ b/gcc/testsuite/gcc.target/loongarch/vector/lasx/lasx-xvpermi_q.c
@@ -27,7 +27,7 @@ main ()
   *((unsigned long*)& __m256i_result[2]) = 0x7fff7fff7fff0000;
   *((unsigned long*)& __m256i_result[1]) = 0x7fe37fe3001d001d;
   *((unsigned long*)& __m256i_result[0]) = 0x7fff7fff7fff0000;
-  __m256i_out = __lasx_xvpermi_q (__m256i_op0, __m256i_op1, 0x2a);
+  __m256i_out = __lasx_xvpermi_q (__m256i_op0, __m256i_op1, 0x22);
   ASSERTEQ_64 (__LINE__, __m256i_result, __m256i_out);
 
   *((unsigned long*)& __m256i_op0[3]) = 0x0000000000000000;
@@ -42,7 +42,7 @@ main ()
   *((unsigned long*)& __m256i_result[2]) = 0x000000000019001c;
   *((unsigned long*)& __m256i_result[1]) = 0x0000000000000000;
   *((unsigned long*)& __m256i_result[0]) = 0x00000000000001fe;
-  __m256i_out = __lasx_xvpermi_q (__m256i_op0, __m256i_op1, 0xb9);
+  __m256i_out = __lasx_xvpermi_q (__m256i_op0, __m256i_op1, 0x31);
   ASSERTEQ_64 (__LINE__, __m256i_result, __m256i_out);
 
   *((unsigned long*)& __m256i_op0[3]) = 0x00ff00ff00ff00ff;
@@ -57,7 +57,7 @@ main ()
   *((unsigned long*)& __m256i_result[2]) = 0xffff0000ffff0000;
   *((unsigned long*)& __m256i_result[1]) = 0x00ff00ff00ff00ff;
   *((unsigned long*)& __m256i_result[0]) = 0x00ff00ff00ff00ff;
-  __m256i_out = __lasx_xvpermi_q (__m256i_op0, __m256i_op1, 0xca);
+  __m256i_out = __lasx_xvpermi_q (__m256i_op0, __m256i_op1, 0x02);
   ASSERTEQ_64 (__LINE__, __m256i_result, __m256i_out);
 
   return 0;