arm: Fix CMSE nonecure calls [PR 120977]

As discussed in https://gcc.gnu.org/pipermail/gcc-patches/2025-June/685733.html the operand of the call should be a mem rather than an unspec. This patch moves the unspec to an additional argument of the parallel and adjusts cmse_nonsecure_call_inline_register_clear accordingly. The scan-rtl-dump in cmse-18.c needs a fix since we no longer emit the 'unspec' part. In addition, I noticed that since arm_v8_1m_mve_ok is always true in the context of the test (we know we support CMSE as per cmse.exp, and arm_v8_1m_mve_ok finds the adequate options), we actually only use the more permissive regex. To improve that, the patch duplicates the test, such that cmse-18.c forces -march=armv8-m.main+fp (so FPCXP is disabled), and cmse-19.c forces -march=armv8.1-m.main+mve (so FPCXP is enabled). Each test uses the appropriate scan-rtl-dump, and also checks we are using UNSPEC_NONSECURE_MEM (we need to remove -slim for that). The tests enable an FPU via -march so that the test passes whether the testing harness forces -mfloat-abi or not. 2025-07-08 Christophe Lyon <christophe.lyon@linaro.org> PR target/120977 gcc/ * config/arm/arm.md (call): Move unspec parameter to parallel. (nonsecure_call_internal): Likewise. (call_value): Likewise. (nonsecure_call_value_internal): Likewise. * config/arm/thumb1.md (nonsecure_call_reg_thumb1_v5): Likewise. (nonsecure_call_value_reg_thumb1_v5): Likewise. * config/arm/thumb2.md (nonsecure_call_reg_thumb2_fpcxt): Likewise. (nonsecure_call_reg_thumb2): Likewise. (nonsecure_call_value_reg_thumb2_fpcxt): Likewise. (nonsecure_call_value_reg_thumb2): Likewise. * config/arm/arm.cc (cmse_nonsecure_call_inline_register_clear): Likewise. gcc/testsuite * gcc.target/arm/cmse/cmse-18.c: Check only the case when FPCXT is not enabled. * gcc.target/arm/cmse/cmse-19.c: New test.
2025-07-08 08:08:21 +00:00 · 2025-07-08 08:08:21 +00:00 · ed520bfcf4
parent aa1e7dd6a3
commit ed520bfcf4
6 changed files with 42 additions and 27 deletions
--- a/gcc/config/arm/arm.cc
+++ b/gcc/config/arm/arm.cc
@ -18983,7 +18983,8 @@ cmse_nonsecure_call_inline_register_clear (void)
 	      call = SET_SRC (call);

 	  /* Check if it is a cmse_nonsecure_call.  */
-	  unspec = XEXP (call, 0);
+	  unspec = XVECEXP (pat, 0, 2);
+
 	  if (GET_CODE (unspec) != UNSPEC
 	      || XINT (unspec, 1) != UNSPEC_NONSECURE_MEM)
 	    continue;
@ -19010,7 +19011,7 @@ cmse_nonsecure_call_inline_register_clear (void)

 	  /* Make sure the register used to hold the function address is not
 	     cleared.  */
-	  address = RTVEC_ELT (XVEC (unspec, 0), 0);
+	  address = XEXP (call, 0);
 	  gcc_assert (MEM_P (address));
 	  gcc_assert (REG_P (XEXP (address, 0)));
 	  address_regnum = REGNO (XEXP (address, 0));
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@ -8623,7 +8623,7 @@
    if (detect_cmse_nonsecure_call (addr))
      {
 	pat = gen_nonsecure_call_internal (operands[0], operands[1],
-					   operands[2]);
+					   operands[2], const0_rtx);
 	emit_call_insn (pat);
      }
    else
@ -8665,10 +8665,10 @@
 	      (clobber (reg:SI LR_REGNUM))])])

 (define_expand "nonsecure_call_internal"
-  [(parallel [(call (unspec:SI [(match_operand 0 "memory_operand")]
-			       UNSPEC_NONSECURE_MEM)
+  [(parallel [(call (match_operand 0 "memory_operand")
 		    (match_operand 1 "general_operand"))
 	      (use (match_operand 2 "" ""))
+	      (unspec:SI [(match_operand 3)] UNSPEC_NONSECURE_MEM)
 	      (clobber (reg:SI LR_REGNUM))])]
  "use_cmse"
  {
@ -8745,7 +8745,8 @@
    if (detect_cmse_nonsecure_call (addr))
      {
 	pat = gen_nonsecure_call_value_internal (operands[0], operands[1],
-						 operands[2], operands[3]);
+						 operands[2], operands[3],
+						 const0_rtx);
 	emit_call_insn (pat);
      }
    else
@ -8779,10 +8780,10 @@

 (define_expand "nonsecure_call_value_internal"
  [(parallel [(set (match_operand       0 "" "")
-		   (call (unspec:SI [(match_operand 1 "memory_operand")]
-				    UNSPEC_NONSECURE_MEM)
+		   (call (match_operand 1 "memory_operand")
 			 (match_operand 2 "general_operand")))
 	      (use (match_operand 3 "" ""))
+	      (unspec:SI [(match_operand 4)] UNSPEC_NONSECURE_MEM)
 	      (clobber (reg:SI LR_REGNUM))])]
  "use_cmse"
  "
--- a/gcc/config/arm/thumb1.md
+++ b/gcc/config/arm/thumb1.md
@ -1874,10 +1874,10 @@
 )

 (define_insn "*nonsecure_call_reg_thumb1_v5"
-  [(call (unspec:SI [(mem:SI (reg:SI R4_REGNUM))]
-		    UNSPEC_NONSECURE_MEM)
+  [(call (mem:SI (reg:SI R4_REGNUM))
 	 (match_operand 0 "" ""))
   (use (match_operand 1 "" ""))
+   (unspec:SI [(match_operand 2)]UNSPEC_NONSECURE_MEM)
   (clobber (reg:SI LR_REGNUM))]
  "TARGET_THUMB1 && use_cmse && !SIBLING_CALL_P (insn)"
  "bl\\t__gnu_cmse_nonsecure_call"
@ -1919,11 +1919,10 @@

 (define_insn "*nonsecure_call_value_reg_thumb1_v5"
  [(set (match_operand 0 "" "")
-	(call (unspec:SI
-	       [(mem:SI (reg:SI R4_REGNUM))]
-	       UNSPEC_NONSECURE_MEM)
+	(call (mem:SI (reg:SI R4_REGNUM))
 	      (match_operand 1 "" "")))
   (use (match_operand 2 "" ""))
+   (unspec:SI [(match_operand 3)] UNSPEC_NONSECURE_MEM)
   (clobber (reg:SI LR_REGNUM))]
  "TARGET_THUMB1 && use_cmse"
  "bl\\t__gnu_cmse_nonsecure_call"
--- a/gcc/config/arm/thumb2.md
+++ b/gcc/config/arm/thumb2.md
@ -537,10 +537,10 @@
 )

 (define_insn "*nonsecure_call_reg_thumb2_fpcxt"
-  [(call (unspec:SI [(mem:SI (match_operand:SI 0 "s_register_operand" "l*r"))]
-		    UNSPEC_NONSECURE_MEM)
+  [(call (mem:SI (match_operand:SI 0 "s_register_operand" "l*r"))
 	 (match_operand 1 "" ""))
   (use (match_operand 2 "" ""))
+   (unspec:SI [(match_operand 3)] UNSPEC_NONSECURE_MEM)
   (clobber (reg:SI LR_REGNUM))]
  "TARGET_THUMB2 && use_cmse && TARGET_HAVE_FPCXT_CMSE"
  "blxns\\t%0"
@ -549,10 +549,10 @@
 )

 (define_insn "*nonsecure_call_reg_thumb2"
-  [(call (unspec:SI [(mem:SI (reg:SI R4_REGNUM))]
-		    UNSPEC_NONSECURE_MEM)
+  [(call (mem:SI (reg:SI R4_REGNUM))
 	 (match_operand 0 "" ""))
   (use (match_operand 1 "" ""))
+   (unspec:SI [(match_operand 2)] UNSPEC_NONSECURE_MEM)
   (clobber (reg:SI LR_REGNUM))]
  "TARGET_THUMB2 && use_cmse && !TARGET_HAVE_FPCXT_CMSE"
  "bl\\t__gnu_cmse_nonsecure_call"
@ -573,11 +573,10 @@

 (define_insn "*nonsecure_call_value_reg_thumb2_fpcxt"
  [(set (match_operand 0 "" "")
-	(call
-	 (unspec:SI [(mem:SI (match_operand:SI 1 "register_operand" "l*r"))]
-		    UNSPEC_NONSECURE_MEM)
-	 (match_operand 2 "" "")))
+	(call (mem:SI (match_operand:SI 1 "register_operand" "l*r"))
+	(match_operand 2 "" "")))
   (use (match_operand 3 "" ""))
+   (unspec:SI [(match_operand 4)] UNSPEC_NONSECURE_MEM)
   (clobber (reg:SI LR_REGNUM))]
  "TARGET_THUMB2 && use_cmse && TARGET_HAVE_FPCXT_CMSE"
  "blxns\\t%1"
@ -587,10 +586,10 @@

 (define_insn "*nonsecure_call_value_reg_thumb2"
  [(set (match_operand 0 "" "")
-	(call
-	 (unspec:SI [(mem:SI (reg:SI R4_REGNUM))] UNSPEC_NONSECURE_MEM)
-	 (match_operand 1 "" "")))
+	(call (mem:SI (reg:SI R4_REGNUM))
+	      (match_operand 1 "" "")))
   (use (match_operand 2 "" ""))
+   (unspec:SI [(match_operand 3)] UNSPEC_NONSECURE_MEM)
   (clobber (reg:SI LR_REGNUM))]
  "TARGET_THUMB2 && use_cmse && !TARGET_HAVE_FPCXT_CMSE"
  "bl\\t__gnu_cmse_nonsecure_call"
--- a/gcc/testsuite/gcc.target/arm/cmse/cmse-18.c
+++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-18.c
@ -1,5 +1,6 @@
 /* { dg-do compile } */
-/* { dg-options "-mcmse -fdump-rtl-final-slim" } */
+/* Make sure FPCXT is not enabled.  */
+/* { dg-options "-mcmse -fdump-rtl-final -march=armv8-m.main+fp" } */

 typedef void (*f)(int) __attribute__((cmse_nonsecure_call));

@ -8,5 +9,5 @@ void bar(f func, int a)
  func(a);
 }

-/* { dg-final { scan-rtl-dump "call unspec\\\[\\\[r4:SI\\\]\\\]" "final" { target { ! arm_v8_1m_mve_ok } } } } */
-/* { dg-final { scan-rtl-dump "call unspec\\\[\\\[r\[0-7\]:SI\\\]\\\]" "final" { target { arm_v8_1m_mve_ok } } } } */
+/* { dg-final { scan-rtl-dump "call \\\(mem:SI \\\(reg:SI 4 r4" "final" } } */
+/* { dg-final { scan-rtl-dump "UNSPEC_NONSECURE_MEM" "final" } } */
--- a/gcc/testsuite/gcc.target/arm/cmse/cmse-19.c
+++ b/gcc/testsuite/gcc.target/arm/cmse/cmse-19.c
@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* This is a duplicate of cmse-18.c, targetting arm_v8_1m_mve, to make sure
+   FPCXT is enabled.  */
+/* { dg-options "-mcmse -fdump-rtl-final -march=armv8.1-m.main+mve" } */
+
+typedef void (*f)(int) __attribute__((cmse_nonsecure_call));
+
+void bar(f func, int a)
+{
+  func(a);
+}
+
+/* { dg-final { scan-rtl-dump "call \\\(mem:SI \\\(reg/f:SI \[0-7] r\[0-7\]" "final" } } */
+/* { dg-final { scan-rtl-dump "UNSPEC_NONSECURE_MEM" "final" } } */