[RISC-V] remove I ext when E ext has been enabled

[Xinlong-Wu]

After patch #88805

I Ext will be added automatically when we running the command like
./build/bin/llc -mtriple=riscv32 -mattr=+e -target-abi ilp32e -verify-machineinstrs llvm/test/CodeGen/RISCV/zcmp-additional-stack.ll

it will generate

	.text
	.attribute	4, 16
	.attribute	5, "rv32i2p1_e2pe"
	.file	"zcmp-additional-stack.ll"
	.globl	func                            # -- Begin function func
	.p2align	1
	.type	func,@function

This patch reset the I ext in FeatureBit when +e has been specify

[llvmbot]

@llvm/pr-subscribers-backend-risc-v

Author: VincentWu (Xinlong-Wu)

Changes

After patch #88805

I Ext will be added automatically when we running the command like
./build/bin/llc -mtriple=riscv32 -mattr=+e -target-abi ilp32e -verify-machineinstrs llvm/test/CodeGen/RISCV/zcmp-additional-stack.ll

it will generate

	.text
	.attribute	4, 16
	.attribute	5, "rv32i2p1_e2pe"
	.file	"zcmp-additional-stack.ll"
	.globl	func                            # -- Begin function func
	.p2align	1
	.type	func,@<!-- -->function

This patch reset the I ext in FeatureBit when +e has been specify

---

Full diff: https://github.com/llvm/llvm-project/pull/92070.diff

1 Files Affected:

• (modified) llvm/lib/TargetParser/RISCVISAInfo.cpp (+9)

diff --git a/llvm/lib/TargetParser/RISCVISAInfo.cpp b/llvm/lib/TargetParser/RISCVISAInfo.cpp
index e22dd6032cb0c..575c9dbad5156 100644
--- a/llvm/lib/TargetParser/RISCVISAInfo.cpp
+++ b/llvm/lib/TargetParser/RISCVISAInfo.cpp
@@ -758,6 +758,8 @@ RISCVISAInfo::parseArchString(StringRef Arch, bool EnableExperimentalExtension,
 }
 
 Error RISCVISAInfo::checkDependency() {
+  bool HasE = Exts.count("e") != 0;
+  bool HasI = Exts.count("i") != 0;
   bool HasC = Exts.count("c") != 0;
   bool HasF = Exts.count("f") != 0;
   bool HasZfinx = Exts.count("zfinx") != 0;
@@ -765,6 +767,10 @@ Error RISCVISAInfo::checkDependency() {
   bool HasZvl = MinVLen != 0;
   bool HasZcmt = Exts.count("zcmt") != 0;
 
+  if (HasI && HasE)
+    return createStringError(errc::invalid_argument,
+                             "'I' and 'E' extensions are incompatible");
+
   if (HasF && HasZfinx)
     return createStringError(errc::invalid_argument,
                              "'f' and 'zfinx' extensions are incompatible");
@@ -852,6 +858,9 @@ void RISCVISAInfo::updateImplication() {
     addExtension("i", Version.value());
   }
 
+  if (HasE && HasI)
+    Exts.erase("i");
+
   assert(llvm::is_sorted(ImpliedExts) && "Table not sorted by Name");
 
   // This loop may execute over 1 iteration since implication can be layered

[topperc]

LGTM

[asb]

Could you please add a test case so we can ensure we don't regress again?